Reefkeepers FAQ's
Part 1
The source of the Reefkeepers FAQ's is available here.1.1 Source Water - City Mains Water Is Not Good Enough
1.1.1 Background
U.S. EPA requirements for water quality from municipal sources are insufficiently pure for reef tank usage. For instance, the EPA standard for Nitrate (as NO3-N) is 10.0 mg/l, over twice the recommended maximum level. Extremely toxic (to inverts) heavy metals such as copper are allowed at levels as high as 1 mg/l.Most public water supplies have contaminants well below the EPA levels and some reef tanks have done fine on some public supplies. In general, however, it is recommended that some form of post processing be performed on public water before it is introduced into the reef tank.
Although some people have access to distilled, de-ionized or reverse osmosis water from public sources, most will use a home sized system to produce their tank water. The two most common systems used are de-ionization resins, and reverse osmosis membranes.
1.1.2 DI filters
De-ionization (DI) units come in two basic varieties: mixed bed and
separate bed. Two chambers are used in separate bed units, one
for anion resins (to filter negatively charged ions), the other
for cation resins (to filter positively charged ions). Mixed bed
units use a single chamber with a mix of anion and cation resins.
DI units are 100% water efficient with no waste water. They are typically rated in terms of grains of capacity (a grain is 0.065 grams). Once the capacity of the unit is reached it either needs to be replaced or recharged (using strong acids and bases). Recharging is normally only an option for separate bed units.
A quick check of the local water quality reports (normally available free from the water supply company) will reveal the water purification capacity of a given DI unit. For example, if a unit rated at 1000 grains is purchased and the local water supply has a hardness of 123 mg/l (Missouri River, USA), then the unit capacity is (1000*0.065)/0.123 = 528 liters = 139.5 gallons of purified water.
Water production rates for DI units varies, but is typically around 10-15 gallons/hour.
Note that some contaminants captured by a DI unit may "break through" long before the unit indicates its capacity has been reached. Silica is a classic example. What happens is that silica is loosely bound to the resins initially, but is replaced by stronger binding materials like carbonates as the resins become exhausted. The use of two DI units in tandem, as mentioned elsewhere in this FAQ, helps to eliminate this problem.
1.1.3 RO Filters
Reverse osmosis (RO) units are normally based upon one of two
membrane technologies: cellulose triacetate (CTA) and thin film
composite (TFC). CTA based systems are typically cheaper and do
not filter as well (90-95% rejection rates). TFC based systems
cost more but have higher pollutant rejection rates (95%-98%).
CTA membranes break down over time due to bacterial attack whereas
TFC membranes are more or less impervious to this. CTA units are
not recommended for reef tank purposes. TFC membranes are very
sensitive chemically to the chlorine found in most water supplies.
It is therefore very important to regularly replace the carbon block
pre-filter associated with all better-grade TFC systems. TFC membranes
are damaged by chlorine so a properly functioning GAC prefilter is
mandatory.
RO filters work by forcing water under pressure against the membrane. The membrane allows the small water molecules to pass through while rejecting most of the larger contaminants.
RO units waste a lot of water. The membrane usually has 4-6 times as much water passing by it as it allows though. Unfortunately, the more water wasted, the better the membrane usually is at rejecting pollutants. Also, higher waste water flows are usually associated with longer membrane life. What this means in practice is that 300 gallons of total water may be required to produce 50 gallons of purified water.
Like any filter, RO membranes will eventually clog and need to be replaced. Replacement membranes cost around $50-$100. Prefilters are often placed in front of the membrane to help lengthen the lifetime. These filters commonly consist of a micron sediment filter and a carbon block filter. The micron filter removes large particles and the carbon filter removes chlorine, large organic molecules and some heavy metals. Of course, the use of prefilters makes initial unit cost more expensive but they should pay for themselves in longer membrane life.
RO units are rated in terms of gallons per day of output with 10-50 gallon/day units typically available. Note that the waste water produced by a RO unit is fine for hard water loving freshwater fish such as Rift Lake cichlids. Some route the reject water to the family garden.
The Spectapure brand of RO units has a good reputation.
1.1.4 Further Comments About Water
The ultimate in home water purification comes from combining the
two technologies and processing the water from an RO unit though a
DI unit. If a very high grade DI unit is used, water equivalent
to triple distillation purification levels can be achieved. Since
the water entering the DI unit can be 50 times purer than
tapwater, the DI unit can process 50 times as much before the
resins are exhausted. This significantly reduces the replacement
or recharging cost of the DI unit. Using two DI units in tandem,
moving the 2nd in as a replacement for an exhausted 1st unit, and
replacing the 2nd unit with a new unit will insure that no undesirable
elements "break through" the exhausted 1st unit and enter your
supply.
If only one filter can be afforded, and waste water is not a concern, then it is recommended that a TFC RO unit with pre-filters be purchased. If waste water is a concern, or if only a small quantity of make-up water will be required (say, for a single 20 gallon tank), then a DI unit would be the preferred choice.
City water is unstable. Many cities modify their treatment process several times a year, dramatically changing its suitability for reef usage. For instance, Portland has great reef water - most, but not all, of the year.
- Calcium (Ca)
- required addition. A range of 400-450 ppm Ca++
(10-11 mM) is recommended. The preferred method is the usage of
Kalkwasser (Limewater) for all evaporation make-up water. The use
of Calcium Chloride (CaCl2) is known to cause problems with alkalinity
(provable by balancing the relavent chemical reactions occuring in the
tank when CaCl2 is added) and contributes to a shift in the ionic
balance of the water which must be corrected via water changes. Still,
CaCl2 is occassionally useful to repair serious Ca++ deficits.
The use of Calcium Carbonate reactors is growing in popularity as a replacement, or sometimes in addition to, Kalkwasser usage. Such reactors use CO2 recirculated through a bed of calcium carbonate (typically crushed coral like Geo-Marine) to reduce the pH and dissolve the calcium carbonate. A small fraction of the recirculated water is allowed to re-enter the aquarium and is replaced in the reactor with fresh tank water on a continuous basis. These systems are considerably more mechanically complex than Kalkwasser systems, often involving CO2 tanks, electrical valves, pH controllers, bubble counters, circulation pumps and related equipment. Once setup and tuned for the calcium demand in a tank, they can often be left alone for months. This low maintenance requirement is a primary benefit of the system, combined with the potential to inject more calcium into the system than kalkwasser alone could do due to kalkwasser's low solubility in make-up water. Note that calcium reactors may add residual CO2 to the system which can fuel algae growth. This extra dissolved CO2 may be purged by either enhanced gas exchange or by adding a small amount of kalkwasser to scavenge the CO2. Newer reactors often have a second carbonate stage to process and utilize this extra CO2. The efficiency of such a second stage is unknown to this author.
A third approach to calcium addition is the use of the newly available two-part ionically balanced solutions. These solutions use CaCl2 as a calcium source, but combine that material via the 2nd part solution with complex ion formulas that negate the normal problems associated with CaCl2 usage. These two-part solutions are relatively expensive for large aquariums but may be cost-effective for smaller tanks relative to the capital required for a calcium carbonate reactor. Others simply find their usage more convenient than the other alternatives. These additives will slowly raise the salinity of the water as a side effect. As always, monitor and correct your salinity as necessary.
Chelated calcium:
The efficacy of chelated calcium products available for reef aquaria is questionable. To the best of our knowledge, there exists no scientific evidence indicating that chelated calcium is especially available to corals and other CaCO3 depositing invertebrates. Nothing is known about the uptake of chelated calcium products by coral. And most importantly, there exists no evidence showing that chelated calcium products support stony coral growth rates in excess of, or even comparable to growth rates documented in aquaria where calcium is supplied as aqueous Ca(OH)2 [kalkwasser.]
Chelated calcium products also interfere with the ability to measure actual calcium levels in the aquarium. In particular, chelated calcium cannot be measured by any kit which uses EDTA titration, including the highly recommended HACH kit.
Until such a time as vendors supplying chelated calcium products make available well conceived, carefully documented uptake and growth studies with their products, or the same experiments are performed and published by third parties, we regard the use of chelated calcium products in the reef aquarium to be experimental at best, especially when kalkwasser and other non-chelated calcium sources are known to us to support the growth and even reproduction of stony corals in the home aquarium.
- Iodine (I)
- SeaChem and Salifert have recently introduced test kits which are finally allowing a view of actual usage in a reef tank. Note that iodine is naturally present in ocean water at relatively low levels (around 0.06 ppm - yes that 60 parts per billion). It is currently considered important for both soft coral growth and hard coral health. It is removed via skimming, activated carbon usage, and assimilation into biomass. It may also be removed by unidentified processes like precipitation.
- Strontium (Sr)
- used rapidly by most hard corals (weekly additions usually performed). Test kits are becoming available but the accuracy of current kits is still questionable. Natural ocean water levels of strontium is around 8 ppm.
- Buffers
- increase alkalinity and control pH. Desired range is 2.5-3.5 meq/L (7-10 dKH) alkalinity. Alkalinity can be raised by the addition of one of many commercial buffer compounds. The addition of kalkwasser (saturated Ca(OH)2 solution - also known as "limewater"), which is often done to maintain calcium levels, will help maintain the alkalinity level. SeaChem's Marine Buffer, Reef Builder and Kent's Superbuffer dKH are popular. The Coralife and Thiel buffer products have had less favorable reviews.
- Iron (Fe)
- Used by alga. Add this if you want good macroalgae growth. Be sure that macroalgae growth is favored or else plague levels of hair algae may result.
- Copper (Cu)
- Used as a medication in fish-only tanks. Copper is highly toxic to invertebrates, even in very small concentrations. DO NOT USE THIS, IN ANY FORM, EVER, IN A REEF TANK OR ANY TANK WHICH CONTAINS INVERTEBRATES. PERIOD!
1.3 Testable Parameters
Note: parts per million (ppm) and milligrams per liter (mg/l) are
virtually identical in seawater and the units are used
synonymously in this document.
1.3.1 Alkalinity
Alkalinity is a measure of the acid buffering capacity of a solution.
That is, it is a measure of the ability of a solution to resist a
decrease in pH when acids are added. Since acids are
normally produced by the biological action of the reef tank
contents, alkalinity in a closed system has a natural tendency to
go down. Additives are used to keep it at a proper level.
Correct alkalinity levels allow hard corals and coralline algae to properly secrete new skeletal material. When alkalinity levels drop, the carbonate ions needed are not available and the process slows or stops.
Alkalinity is measured in one of three units: milliequivalents per
liter (meq/l), German degrees of hardness (dKH) or parts per
million of calcium carbonate (ppm CaCO3). Any of the units may be
employed but dKH is most commonly used in the aquarium hobby and
meq/l is used exclusively in modern scientific literature. The
conversion for the three units is:
A word of caution about the ppm CaCO3 unit is in order. The 'ppm
CaCO3' unit reports the concentration of CaCO3 in pure water that
would provide the same buffering capacity as the water sample in
question. This does not mean the sample contains that much CaCO3.
In fact, it tells you nothing about how much of the buffering is
due to carbonates, it is only a measure of equivalency.
Alkalinity is often confused with carbonate hardness since both
participate in acid neutralization and test kits may express both
in either of the three units. However, carbonate hardness is
technically a measure of only the carbonate species in equilibria
whereas alkalinity measures the total acid binding ions present
which may include sulfates, hydroxides, borates and others in
addition to carbonates. In natural seawater, though, carbonates
make up 96% of the alkalinity so equating alkalinity with
carbonate hardness isn't too far off. As long as you're using a salt
mix which yields an ion mix close to that of Natural Sea Water (NSW)
you can also make this assumption. Some salt manufacturers alter
the alkalinity component of their mix to increase the percentage of
borates to (bi)carbonates in order to maintain a stabler pH in the
aquarium. We do not feel this is good, and highly recommend you
watch the trade magizines for reports on borates in salt mixes.
(OK, OK, here's a preview... Instant Ocean does NOT have abnormal
borates based on initial testing.)
Recommended values for alkalinity vary depending on who's work you
read. Natural surface seawater has an alkalinity of about 2.4
meq/l. Following are levels recommended by various authors.
From John Tullock (1991) "The Reef Tank Owner's Manual":
The chemistry of how alkalinity, pH, CO2, carbonate, bicarbonate,
and other ions interrelate is fairly complex and is beyond the
scope and detail of this document.
Some recommended test kits for alkalinity are the SeaTest kit, the
inexpensive Tetra kit and the LaMotte kit. The SeaTest kit
measures in division of 0.5 meq/l or, if the amount of solution is
doubled, 0.25 meq/l. The SeaTest kit uses titration in which the
acid and indicator are included in the same reagent. The LaMotte
kit is a little more expensive, though still fairly cheap, and is
somewhat more accurate. The unit of titration is 4 ppm CaCO3
although in practice, one drop from the titration tube may be up
to twice this amount making the resolution about 0.15 meq/l. The
Lamotte kit has a separate indicator tablet and acid reagent which
is a nice feature.
Calcium hardness test kits are different from alkalinity kits.
Some people have reported difficulties with the LaMotte calcium
hardness kit. The Hach 'Total Hardness and Calcium' kit has not
had these reports. Both express results in ppm CaCO3. The
relationship between CaCO3 and Ca++ is:
Note that it is perfectly normal for the pH of a tank to swing
considerably. There is a daily pH cycle where the pH is lowest
just after the end of the dark period and highest sometime before
the end of the light period. Having a pH range from 7.9 to 8.4
is not unheard of. Larger swings are probably indicative of
low buffer levels or poor gas exchange.
Different authors cite varying upper nitrate values permissible.
No higher than 5 ppm NO3- is a good number with less than 0.25 ppm
recommended. Unpolluted seawater has nitrate values below
detectable levels of hobbyist test kits, so "unmeasurable" is the
goal to strive for.
Most test kits measure nitrate-nitrogen. Do not forget to
multiply by 4.4 to get the ionic nitrate reading. LaMotte makes a
nitrate test kit that will measure down to 0.25 ppm NO3-N.
The Hach kit, which measures down to 0.02 ppm N03-N has basic
chemistry problems in saltwater and is no longer recommended.
The use of kalkwasser has been closely tied with reduction in
phosphate levels. This may be due to precipitation of the phosphates
at the kalkwasser injection site, or, more likely, due to increased
export via skimming due to the associated higher system pH.
Note: If your tank is between 75F and 80F, this means you
should try and keep your Specific Gravity around 1.0230 to 1.0235.
For all practical purposes, the scale is linear between data points,
so you can simply extrapolate between table entries. For instance,
78F is 3/5 the distance between 75F and 80F; the difference in corrections
is 0.0024-0.0017 = 0.0007. 3/5th of 0.0007 is 0.0004. Add the offset
0.0004 to the base value for 75F of 0.0017 and you get a correction
value for 78F of 0.0021.
It is fairly common in literature to see references to salinity in terms
of Parts Per Thousand (PPT). For salinities in the range we are interested
in, the conversion formulas are:
The use of live rock greatly increases the bio-diversity in a tank.
However, its primary purpose is to provide a home for bacteria that
provide the biological filtration for the aquarium.
Cheap rock has low amounts of coralline algae and tends to grow
hair algae well. It may be suitable for a soft coral only tank.
Hair algae free coralline encrusted live rock (high quality
Florida and/or pacific (Marshall and Tonga Island) rock is highly
desirable. "Berlin" style tanks use high quality live rock (and
protein skimming) as the primary filtration method with great
success.
Although an old rule of thumb states that 1-2 lbs of live rock
is required per gallon of tank size, the wide range of available
rock makes the rule pretty inaccurate. It is suggested that a
visual method be used, consuming approximately 1/3rd of the tank
volume with rock - leaving 2/3rd of the volume in open water. You
should probably only use the rule of thumb as a sanity check. For
instance, 10 lbs of the best rock would be too little for a 75 gallon
tank, no matter how good the rock is. Likewise, 300 lbs would be
overkill.
Live rock is typically "cured" prior to introducing other life forms
in a tank. This curing process is, in its shortest form, simply a
period of time to allow dead and dying organisms on the rock a
chance to decay. Any time live rock is moved, some organisms will
probably die. Shipping rock submerged in oxygenated water (very
expensive) is the only practical way to minimize this die-off.
Live rock should be cured in a container with excellent protein skimming,
activated carbon, excellent oxygenation and water motion. There is a very
real danger of anoxia when freshly shipped live rock is placed into a
curing vessel. Unless the dissolved oxygen concentration is kept high in
the curing vessel, the bacterial bloom fed by the initial die-off will
cause the curing vessel to become anoxic, and even more life will
perish. Therefore gas exchange and water motion are crucial. Protein
skimming helps to remove organics before they are consumed by bacteria.
Addition of a cycled biological filter may reduce the severity and
lethality of the ammonia spike when curing live rock.
It is recommended that fresh live rock be allowed to cure for at least
one month prior to the introduction of any other life forms in a newly
setup aquarium. There may well be advantages to waiting between
three months and a year, with the tank running in normal mode (full
circulation, heating, lighting, etc), before adding other life forms
in order to allow the biodiversity naturally present on the rock to
stabilize.
Required equipment. Don't undersize. Common wisdom is that you
can't overskim a tank. Recent developments in using down-draft
style skimmers, with ETS being the first commercial instance, have
raised the possibility that it's now possible to overskim a tank.
This is stated with a lot of caution, we still feel that its impossible
to overskim using airstone or venturi driven skimmers of reasonable
size. (Using a 8" x 6' counter-current skimmer processing 600 gph
of air on a 20 gallon tank could overskim it - be reasonable!)
Unfortunatly, there is no formula to determine the required size
of a skimmer. Amount of organic waste generating organisms (fish,
coral, live rock, etc.) will obviously be the primary variable.
All skimmers should be filled with tiny bubbles and have a milky
white appearance. Any skimmer that doesn't match that requirement
is not working optimally.
There are some basic rules-of-thumb on minimum skimmer sizing
however: A skimmer should process at least one tankful of air
and one tankful of water per hour. For most tanks, the water rate
is easy. The air rate however is not. Most counter current
(explained below) skimmers are under-supplied with air. If you
have a sealed skimmer where the air can only exit from one fitting,
its easy to measure the flow rate. Simply take a large plastic
bag (something in the 2 gallon size works well), empty it, and
place it over the air exhaust port. Time how long it takes to
fill and do the math.
Three basic styles of skimmers exist: counter current air driven,
venturi driven, and down-draft. All styles work fine, all have
tradeoffs. All require some tuning. Expect to spend some time over
the first month or so learning how to keep your skimmer tuned.
The water pump injects the water to be skimmed into the unit.
Some people use gravity to feed surface overflow water to the
skimmer or divert part of the main circulation pump's return flow
into the skimmer to eliminate the need for a dedicated pump.
Otherwise a powerhead in the sump usually suffices for the water
pump. Some arrangement should be made to gather surface water
for all forms of skimmers.
The air pump must be large enough and a sufficient number of air
stones must be driven to make the skimming column milky white. In
some smaller skimmers one medium sized air pump like a Tetra Luft G
and one air stone will be sufficient. Other skimmers need a lot more
to perform optimally.
Speaking of air-pumps, we find it baffling that folks who would
consider spending $250 for a water pump to drive a different style
skimmer totally reject spending anything on that order for an air-pump.
When comparing skimmers, please be reasonable. Don't expect a
counter-current airstone skimmer driven by a Tetra Luft to function
as well as a venturi or down-draft skimmer driven by an Iwaki RLT-75
water pump costing around 10 times as much.
Air driven skimmers should use limewood air stones which will need
to be replaced from time to time. Cheap limewood air stones have
a reputation of needing to be replaced much more often than high
quality stones. Coralife limewood air stones have a good
reputation. Air stone replacement rate depends on your tank and
skimmer; some people need to change them every 2 weeks others only
after 3-4 months. It is believed that having a high air-flow prolongs
the life of airstones. Some folks are experimenting with using VERY
high quality fine-pore ceramic airstones, such as those available
from Aquatic Eco-Systems.
A.J. Nilsen recommends a 1x tank volume per hour turnover of both
water and air by counter current air driven skimmers. Others feel
each skimmer has an optimal rate of air and water processing and
that if more skimming is desired then more or bigger skimmers
should be added rather than trying to operate the current one
beyond its optimal performance range.
Some hold that any skimmer under 4' high and 4" in diameter is too
small for anything over about a 20 gallon reef.
A particular commercial venturi skimmer may or may not come with a
water pump. If it does supply a pump, it may or may not be
sufficiently large to run the skimmer properly. At least some of
the venturi skimmers easily available are not very well designed.
Venturi valves require occasional cleaning of the air opening.
This is as simple as reaming the opening out with a pipe cleaner
every few days. An acid bath may be required if the unit clogs or
gets coated with mineral deposits.
Most venturi style skimmers are more compact than CC skimmers.
Manufacturers state that they are more efficient, since they
(supposedly) inject more air. Many suspect that design constraints
(back pressure severely affects venturi performance) have more
to do with the manufactured height (who would want a top injected
4' skimmer with air only in the top foot of water?). Properly
designed venturi skimmers are tall to maximize air contact time,
and require pumps that can handle backpressure.
The cost of ETS skimmers is relatively high, but expected to drop as
competitors enter the market. Cost of operation is high due to the
need for a huge water pump. The use of Iwaki 55s and 70s on base
unit ETS skimmers is common. This size skimmer is appropriate for
a 70-135 gallon tank. e.g. The skimmer pump may be larger than
many use for the main tank circulation.
Construction of down-draft skimmers is easy, designing one to
function optimally is not.
As previously mentioned, this is the first style skimmer where the
authors of this FAQ have even considered the possibility of over-
skimming a tank. With this style skimmer, bigger may actually
not be better...
Venturi skimmers, due to the large water pump needed, have a
higher initial purchase price than CC units for the same amount of
skimming. Many venturi skimmers are poorly designed, with woefully
inadequate pumps to drive the venturi valve. Remember: Its not
the technology that makes a skimmer good, its the amount of air and
water processed that makes it good. The technology is just a method
to reach that goal. There are plenty of counter current skimmers
that out-perform venturi based skimmers, and visa-versa.
The operational cost of a venturi unit is basically just the
electricity bill. A CC unit must sum in electricity consumption
for the water pump and air pump (usually small) plus air stone and
diaphragm replacement. Which one is more cost effective for you
depends upon which equipment you had to buy to run the skimmer
properly, your electricity rate and how often air stones need to
be replaced. Most people find CC skimmers less expensive to both
purchase and operate for the same amount of skimming.
Venturi skimmers are less cumbersome in appearance and in
operation. They are usually smaller and quieter. They are on the
whole more hassle free. The powerful pump required for venturi
skimmers may, however, add considerable heat to the water.
When large down-draft skimmers are driven by an appropriate pump,
they outperform venturi skimmers that use pumps of similar power
consumption. That is, they are more "efficient". Once setup and
past their 3-14 day break-in period, down-draft skimmers require no
maintanence beyond the periodic cleaning that all skimmers require.
There is some debate over down-draft skimmers vs properly run
counter-current airstone skimmers. A counter current skimmer can be
provided with a similar air and water flow for somewhat less initial
money. Note that we are not comparing $1200 ETS systems to $30
Coralife co-current skimmers here, but rather systems about the same
physical size.
Of the three skimmer designs, counter current skimmers are the most
plankton friendly. Although some small plankton will be removed as
particulate material, it is at least conceivable for plankton to
survive the trip through the water pump and through the bubble
column. Venturi skimmers are much harder on plankton, since significant
pressure is applied to them as they pass through the venturi valve.
Down draft skimmers are assumed to kill anything larger than single
cell organisms that pass through them due to the force and mechanical
stress the water is exposed to.
One general note on water pumps: The amount of heat added to
the water varies by brand, design, usage, and placement. Basically,
the more efficient the pump (gallons delivered at a given pressure
for a given power usage), the cooler it will run. Restricting
the output of the pump will generally increase the water temperature.
(Never restrict the intake of a centrifugal pump!) Obviously, an
air cooled pump will increase your tank temperature less than a
submersible (and therefore tank water cooled) pump will.
GAC has the ability to very rapidly remove dissolved organic compounds
which cause the water to yellow. Indeed, failure to remove these
compounds is a excellent way to determine when your carbon has been
exhausted. A simple test consist of collecting (even temporarily)
5 gallons or so of tank water in a white plastic container. If the
water appears yellowish, the carbon should be replaced.
WARNING: If the tanks water is significantly yellow, carbon should
be replaced very slowly, like a gram-per-gallon at a time. Failure
to do this may drastically improve the water's clarity, allowing more
UV light to reach the organisms. Corals have been known to bleach and
die after large carbon changes due to this rapid light transmission
change.
Many members of the group of authors do not use mechanical filtration.
They believe that such systems filter out the plankton that is used
as food by many marine organisms. Some members use "live sand" setups,
with detritivores. Others routinely siphon accumulated detritus.
Use of a mechanical filter for short periods may help when attempting to
resolve specific problems, such as a hair algae outbreak.
Remember, NO3- is an indicator for other waste compounds (e.g. dissolved
organics) which are not easily measureable and these compounds will also
be present in abundance.
In most healthy natural communities, particularly coral reefs,
dissolved nutrients are scarce. In aquaria, by contrast,
nutrients in the form of dissolved inorganic nitrogen, or DIN, (a
collective term for ammonia, nitrites, and nitrates) accumulate
very rapidly as fish and other organisms excrete these wastes.
The most basic problem in any aquarium is limiting the
accumulation of DIN.
In reef aquaria, DIN is consumed by the community of organisms on
the live rock. It is uncertain what relative contribution is made
by bacteria as opposed to algae, but it is certain that the live
rock community as a whole can remove a substantial amount of DIN
from a reef aquarium. In fact, it is quite possible to run a reef
tank with no biological filtration (DIN consumption) other than
that which takes place on the rock. This method is part of what
is now known in the United States as the "Berlin school" of
reefkeeping.
Other schools of thought utilize additional biological filtration
in separate filters. Traditional reef tanks supplement the
filtration provided by the reef (often not acknowledging the role
of the reef itself) with bacteria-based trickle filters. Many
readers probably learned this technique first, as it has been the
dominant method in the United States amateur hobby for some time.
Yet another approach uses algae, which are also capable of
utilizing inorganic nitrogen directly. An algae filter, or algal
scrubber as it is usually called, is simply a biological filter
which utilizes a colony of algae rather than bacteria as consumers
of inorganic nitrogen.
Algal scrubbers are not new; they are discussed in Martin Moe's
(1989) excellent Marine Aquarium Reference: Systems and
Invertebrates, for example. However, algae filters have been
regarded in the past as too bulky and inefficient to be the sole
filter for a aquarium. The recent surge of interest in algal
scrubbers seems to have been generated by Adey and Loveland's book
Dynamic Aquaria (1991). They discuss both techniques which
allow an algal scrubber to be compact and efficient and also a
number of arguments as to why they are preferable to other
filtration methods.
One reason to use an algal scrubber according to Adey and Loveland
is that it mirrors the way DIN is cycled in nature. They claim
that perhaps 70-90% of the DIN in reef communities is consumed by
algae, rather than by bacteria. The two methods produce rather
different water chemistry; for example, algae are net producers of
oxygen and remove carbon dioxide, while a bacterial filter
consumes oxygen and produces carbon dioxide. They argue that it
should be easier to maintain the type of water chemistry found
over a natural reef by relying on an algal scrubber.
Also, algae remove the nitrogen from the water in order to build
tissue, while filter bacteria simply put it into a less toxic
form. The excess nitrogen can be removed completely by periodic
algae harvests, while dissolved nitrogen in the form of nitrate is
not as easy to remove. Adey and Loveland claim that their methods
can bring levels of DIN down to a few hundredths of a ppm, far
below (in their opinion) the levels reachable with other methods.
A related argument in favor of algal scrubbers is that stability
in natural ecosystems comes from locking up nutrients in
biomass, not in allowing it to be free in the environment. An
algal scrubber does precisely this, while a bacterial filter
converts it to free nitrate dissolved in the water.
A final reason to use an algal scrubber according to Adey and
Loveland is that many other kinds of filtration (including protein
skimmers) remove plankton from the water. An algal filter
naturally does not do this, and can actually provide a refuge for
some forms of plankton. The importance of this effect is,
however, a matter of some debate.
As compelling as some find the above arguments in theory, there
seem to be serious problems with algal scrubbing in practice.
Many attempts by public aquaria at implementing reef tanks using
only algal scrubbing have been failures. In particular, it seems
difficult to find successful long term success with Scleractinia
(stony corals) in such tanks, and those success stories which can
be found are quite difficult to verify and often contradicted by
others.
Various public and private aquaria have used algae scrubber
filters on their reef aquaria, with disastrous results. The
microcosm at the Smithsonain Institution has yet to keep
scleractinia alive for more than a year. While Dr. Adey has stated
how well corals grow in this system, those viewing the system have
failed to find these corals. In an interview with Jill Johnson,
one of the techs responsible for the Smithsonian tank, she stated
to Frank M. Greco that frequent collecting trips were needed to
keep the system stocked with live scleractinia.
The Pittsburgh AquaZoo also has a "reef" tank based on Dr. Adey's
algal scrubbers. This tank is nothing more than a pile of rocks
covered with filamentous green algae, and the water is quite
yellow (as is the Smithsonian tank) from the presence of dissolved
organics (ORP readings have been around 165). As with the
Smithsonian tank, scleractinia do not survive longer than a few
months. The same applies to soft corals as well. When I (Frank M.
Greco) saw this tank on May 3, 1993, there were no living corals
to be found even though a collecting trip to Belize was made
several months earlier and 81 pieces of living scleractinia were
brought back. There were, however, two piles of dead Atlantic
scleractinia: one right behind the tank and the other in the
greenhouse housing the algal scrubbers.
The Carnegie Science Museum (Pittsburgh, PA) also uses an algal
scrubber system, but with significant modifications. This tank
looks the best of the three. There are several species of hardy
Scleractinia and soft corals that are doing quite well. The water
is clear (a bit cloudy). The major differences between this system
and the other two is the use of carbon, a small, barely
functioning algal scrubber, about 1000 lbs. of excellent quality
live rock (Florida), water changes, and the addition of Sr and Ca.
The last system I know of that uses an algal scrubber is the Great
Barrier Reef Microcosm in Townsville, Australia. As of this
writing, the system is not maintaining live Scleractinia, and
frequent collecting trips are needed in order to replenish the
exhibit. It should also be noted here that while Dr. Adey has
claimed in his book Dynamic Aquaria that corals have spawned in
this system, what he doesn't mention is that the corals which
spawned were collected only months before the known spawning
season. From these few examples, it should be clear that algal
scrubbers are NOT to be used in systems containing live
scleractinia.
[Some theories, observations, and other comments withdrawn.]
The weight of evidence at this point seems to be against the use
of algal scrubbing in reef tanks, and the method should be
considered to be experimental. Beginners particularly are
advised to avoid this technique until they have considerably more
experience with reefkeeping. The advanced aquarist may well wish
to experiment with this interesting and controversial method, but
it would be unwise to risk the lives of an entire reef tank full
of coral. Such experiments should progress slowly, beginning with
the most hardy of inhabitants. Many of the objections center on
stony coral survival, and it is possible that scrubbed tanks with
fish and hardy invertebrates may do quite well.
If you decide to have a live sand substrate bottom, you should
include several creatures that will turn-over, or otherwise, move
the sand around. Recommendations include: Sea Cucumbers, Brittle
Starfish, Serpent Starfish, Orange Spot and Golden Headed Sleeper Gobies, Yellow
Jawfish, Watchman Gobies, and other detrivores. A mix of the above
is recommended, since each creature moves the sand around differently.
If you use sea cucumbers make sure there is NO way one can enter into
any pumps. If a cucumber gets stuck in a pump, it will potentially
release extremly toxic substances into your tank. The only remedy is
to start your reef tank over since no known anti-toxin exist. Yes,
everything may die in your tank (strong skimming may save the day, but
don't count on it).
Live sand has a reputation of eliminating the final traces of nitrates
in otherwise well run tanks. It also provides an environment for
additional bio-diversity in the tank. Additionally, some feel that
the chemical balance and stability of a tank's water is improved when
live sand is present.
Note that live sand usage should still be considered experimental.
Usage is dependant upon have the sand sifted and otherwise moved
around to prevent detritus from accumulating. Many people have reported
problems keeping their turn-over creatures alive for long periods
of time. Some have not seen the reported nitrate reductions. Keep
in mind that many reef tanks have operated for years without a substrate
and have no detectable nitrate concentrations. Use of very fine sand
has been linked to hydrogen sulfide production in tanks. On the other
hand, use of live sand definitely allows for a more diverse bio community.
A lighting analysis is now presented. Everyone has their own sets
of numbers they would plug in here, for now let's assume the
following for comparison. Many will debate the specifics found below.
Feel free to substitute your own numbers, but the methodology is
sound.
Bulb cost and performance:
There is a greater variety of lamps available for NO than VHO.
OTOH, it seems that NO lamps can be operated at VHO power levels,
with a somewhat shortened lifetime (the higher replacement
frequency is offset by lower lamp cost), so this may not be an
issue.
The initial installation cost (basically the ballast cost) is
higher for VHO, even in terms of per-lumen, but this is a pretty
small part of the total cost of the lighting system over the
years.
NO requires more lamps for a given total light intensity, so you
may not be able to fit enough NO bulbs in your hood if you need a
lot of light.
MH seems to be a winner in both replacement and operating costs.
The color spectrums available in MH lights has improved substantially
recently with the advent of 10K and 20K bulbs. 10K bulbs are
becoming very popular as the sole light source for reef tanks. 20K
bulbs are often being used in conjunction with older lighting systems
to provide a more balanced light mix.
On the flip side, MH bulb vendors have had some horrible
quality problems, and obscene pricing practices. Recent testing
has also determined that MH ballast have a manufacturing acceptable
level of output variance that may result in totally unacceptable
differences in individual bulb spectrum output.
MH vs fluorescent also gets into the aesthetic and biological
considerations. Water surface ripples causing light ripples in
the aquarium and room are pronounced with MH lighting. Many
people appreciate this effect. Some (e.g. Julian Sprung) feel the
variation in light intensity is actually important for some
photosynthetic organisms.
Many people are under the impression MH runs hot, whereas
fluorescent doesn't. In reality, the efficiencies are similar,
with MH producing slightly LESS heat than the equivalent
fluorescent. The difference is MH dumps all the heat in a small
space so the local temperature rise is greater. But if you want
to try to get rid of the heat it's actually easier to do it if the
heat is concentrated in one spot, since its easier to get rid of a
small amount of very hot air than a very large amount of warm air.
A separate issue is the
selection of a conventional ballast vs an electronic one. There is
no doubt the electronic ones are more expensive to purchase, but
the savings in electricity offset the high initial cost in a year
or so. Also, if heat production is an issue, the electronic
ballasts are to be favored. The Icecap VHO electronic ballast is
widely advertised, however its advertised claims are also
frequently questioned. Advance makes a series of NO electronic
ballasts.
There are yet two more issues, for which there are a lot of
questions and too few answers. Specifically, the short term
flicker in light intensity, and radiated electromagnetic fields.
Fluorescent lamps on conventional ballasts flicker at 120 Hz,
which is above the human visual response, so we don't see it
(actually, the flicker is both in intensity and spectrum). But
that doesn't mean other creatures can't see it, or whether they
benefit or are disadvantaged by it. Electronic ballasts cause
flicker at ~30 KHz; it is seriously doubtful that any creature can
detect this, so it would appear constant.
The flicker doesn't have to be visible to have an effect: it
causes any movement to appear strobed, and this may affect the
feeding efficiency of visual hunters.
The fields issue is even more obscure. At least many
cartilaginous fish (sharks, rays, etc) are known to be extremely
sensitive to electric fields, and many crustaceans are sensitive
to magnetic fields (crabs with pieces of magnetite in internal
sensory organs). Fluorescent lamps, with the large area they
cover, tend to radiate (using the term pretty loosely) fairly
strongly, but MH, and the wiring, and the ballasts can radiate
too. It's unknown how significant this could be in an aquarium
(but its known sharks preferentially attack undersea cables
because of the fields, so there is at least indirect evidence its
an issue worth some thought).
BTW, a grounding device reduces the level of induced voltages in
the tank, but this is achieved at the expense of increased induced
current, so its effect (if any) may depend on the species. Also,
note if you have a titanium coil chiller on the tank, it is probably
already grounded through the chiller, and an additional ground may in
fact increase the electric current. This should not be an issue
with epoxy or ceramic coated chiller coils.
The estimates include the cost of the initial set-up. There is
also a section on ongoing costs. The ongoing cost will vary
greatly, especially considering that you will stock your tank
gradually. Keep in mind that you always end up spending more than
you think you will. If you set up a reef, you will end up stopping
at the hardware store and/or aquarium store for timers, extension
cords, GFIs (a must!), buckets, hoses, and books, don't forget
books. You should read a few books on reefkeeping before even
planning your setup. An extra hundred bucks or three is going
to leak out of your wallet whether you plan on it or not.
Another factor is that more advanced equipment may translate into
less or easier maintenance. You should keep in mind that if you
go with inferior equipment, maintaining the tank will be more
work. More expense will mean more automated equipment and less
work. Also, some varieties of inverts require more exacting
condition, more light, etc. Plan your purchases so that the stock
you buy has a chance of surviving with the equipment you are
using. If you have a bare minimum system, stick hardy items like
soft-corals, polyps, mushrooms, etc.
The minimum included is close to rock-bottom as far as an
acceptable systems goes. It assumes that you are DIYing much of
the equipment as cheaply as possible. The maximum in the estimate
is in some areas a little extravagant but not unreasonable. A good
system that is not extravagant could be put together for somewhere
in between the two extremes. Perhaps, for 1.25 to 2 times the
minimum, you would have a very nice system. Some areas are easier
to cut-corners on than others and some of the initial cost may be
incremental, like buying test kits as needed. Also, you may have
some of the equipment already from previous set-ups or be buying
it used. Seek out the advice of an experienced reefkeeper when
planning and pricing your system.
You probably should start with the snails as soon as the
live rock is in the tank. You don't have to have any fish
if you don't want any. You don't have to have inverts either
although that is probably why you set up a reef tank. Just
quality live-rock is very of nice to look at but sooner or
later you will likely want something else in your tank. The
invert stocking will be very incremental and should be.
It is not heathly to add a lot of stock at once. You can
spread your stocking over several years. You could spend
anywhere from say $100 to $750 on the micro-reef and $200 to
$10,000 on the mini-reef.
[As an aside, there is an imperial unit of alkalinity and hardness
which is 'grains per gallon'. The water softening industry uses
this unit. 1 gpg = 17 ppm CaCO3.]
Albert Thiel (1989), in "Small Reef Aquarium Basics" recommends
5.35-6.45 meq/l. This is an artificially high level which may
initiate a "snowstorm" of CaCO3 precipitate. Most reef aquarists
do not believe in such extreme and unnatural levels and recommend
3.0-3.5 meq/l as a good range instead.1.3.2 Calcium
Calcium content is referred to as 'calcium hardness' and is
measured either in parts per million of calcium ion (ppm Ca++) or
parts per million equivalent calcium carbonate (ppm CaCO3).
Calcium hardness is often confused with alkalinity and carbonate
hardness since the 'ppm CaCO3' unit may be used for all three. As
with alkalinity, a calcium level expressed as X ppm CaCO3 does not
imply that X ppm of calcium carbonate is present in the tank; it
merely states that the sample contains an equivalent amount of
calcium as if X ppm of CaCO3 were added to pure water. The
reading also does not tell you how much carbonate is present.
The results from a test kit reading in ppm CaCO3 may be converted
to the molar concentration scale by dividing by 100.
Calcium levels of natural surface seawater are around 420 ppm
Ca++ (10.5 mM). In a well running reef tank you will notice, sometimes
dramatic, calcium depletion. Calcium addition in some form is
essential. A calcium level above 400 ppm is required and a range
of 400-450 ppm Ca++ is recommended. Most reefkeeping books (see
bibliography) explain the options for calcium addition.
1.3.3 pH
The suggested reef tank range is 8.3 to 8.4. The pH should hold
its own unless alkalinity is low. If alkalinity is OK but pH is
low there is probably a buildup of organic acids or a serious lack
of gas exchange resulting in the retention/accumulation of CO2
which lowers pH.1.3.4 Nitrate (NO3)
Two units are used to measure nitrates: nitrate (NO3-) and nitrate
nitrogen (NO3-N or just N). The ratio is:
Nitrates themselves may not be a problem but serve as an easily
measured indicator of general water quality. Many hard to test
for compounds like dissolved organics tend to have levels that
correlate well with nitrate levels in typical tanks.1.3.5 Phosphate (PO4)
Phosphates, along with nitrates, are a primary nutrient of algae.
Tanks with "high" levels of phosphates tend to be infested with
hair algae. All authors cite zero ppm PO4 as a good goal. An
upper level 0.1 ppm is recommended by Tullock (1991) with less
than 0.05 ppm given by Thiel (1991).1.3.6 Specific Gravity
Short form: Specific Gravity is temperature dependant. See the
next table for a quick lookup of the recommended hydrometer readings.
They are based upon our recommended S.G. of 1.025 at 60 degrees F.
Degrees F.
Hydrometer reading.
50
1.0255
55
1.0252
60
1.0250
65
1.0246
70
1.0240
75
1.0233
80
1.0226
85
1.0218
(rather hot for most tanks)
90
1.0210
(very hot for most tanks)
In more detail: 1.025 recommended for reef tanks. Note that
virtually all hydrometers are calibrated for measurements at a
temperature of 60 F. Included below is a short table of temperature
adjustments. Add the value shown to your hydrometer reading to get an
accurate reading.
Degrees F.
Correction
50
-0.0005
55
-0.0002
60
0.0000
65
0.0004
70
0.0010
75
0.0017
80
0.0024
85
0.0032
90
0.0040
For example: If the hydrometer reads 1.0235 at 80F, the actual
Specific Gravity is 1.0235 + 0.0024 = 1.0259
Here is a short table of some common values:
Salinity
Specific Gravity
20 PPT
1.0135
25 PPT
1.0174
30 PPT
1.0212
35 PPT
1.0251
* Typical Ocean Value *
40 PPT
1.0289
1.4 Water Changes
"The solution to pollution is dilution". Water changes are used to
correct problems. Minimal changes of 5%/year when all is set up
and running smoothly may suffice. Some feel that an occasional
water change of about 20% every 1-3 month is a reasonable safety
net that may help prevent contaminant buildup, shift in ion balance,
and trace element depletion problems. Others recommend 5%-10% per week.
2.0 Filtration and Equipment
2.1 Live Rock
Live rock is simply old reef substrate that has become the home
to multiple small plants and animals. Pieces vary in size and shape
from baseball size to dinner plate size in typical tanks. In large
tanks (> 500 gallons) very large pieces of live rock tend to be used.
These pieces may individually weight up to 85lbs (about the limit of
what one person can handle). 2.2 Protein Skimmers
Protein skimmers are devices that mix large volumes of air and
tank water to produce foam. This foam is then collected and
disposed of. The foam will contain a fair amount of particulate
material, lots of organic material that would otherwise breakdown
and pollute the tank, and unfortunately some trace elements like
iodine. Besides removing organic material, skimmers play a key
role in maintaining proper O2 and CO2 levels in tank water. For
instance, having a large skimmer that processes a large amount of
air will allow larger quantities of kalkwasser addition, both due
to increased evaporation, and due to improved CO2 absorbtion capacity.2.2.1 Counter Current Air Driven Protein Skimmer
These skimmers usually require three pieces of equipment typically
not sold with them: an air pump, air stones and a water pump.
Total skimmer cost depends upon the kinds of equipment needed to
run the skimmer properly.2.2.2 Venturi Protein Skimmers
These skimmers use the Bernoulli effect of the venturi valve to
inject air bubbles into the water. This obviates the need of an
air pump and air stones. The penalty is that a relatively large,
high pressure (read expensive and power hungry) dedicated water
pump is mandatory for the venturi unit to inject sufficient
amounts of air.2.2.3 Down-draft Skimmers
This style skimmer was first commercially introduced as the ETS skimmer.
Currently there are several on the market. This skimmer using a high
pressure stream of water injected downward into a column of bio-
balls to suck air into the water stream and break the air up into
tiny bubbles. They do this very well,
with some casual testing indicating air movement on the order of
10 times the volume of equivalently pumped venturi models.2.2.4 Protein Skimmer Considerations
Below are some pros and cons of three styles of skimmers. Some
people will debate some of the statements.2.3 Granular Activated Carbon
Some debate about its usage. Most use it at least a few days a
month, some continuously. Many brands have problems with
phosphate leaching.2.4 Other Chemical Filter Media
X-Nitrate, X-Phosphate, Polyfilters, Chemi-pure, etc. - probably
not needed in an established, balanced reef aquarium. A prominent
manufacturer of these materials was either unwilling or unable
to supply capacities for removing the named compounds from
seawater. They may cause adverse reactions in some inverts.
2.5 Mechanical filtration
This is an area of interest currently being debated. Originally
the FAQ stated:
Good idea to pre-filter skimmer water. Floss works fine and is
cheap and disposable. Sponges work well, but require cleaning
twice a week or so. Natural sponges with a medium fine or fine
pore size are recommended. Some people don't use mechanical
filtration, allowing detritus to settle in places for removal by
siphoning. Some of these people make dedicated "settling tanks"
to trap debris in a convenient place.
Julian Sprung suggests not pre-filtering skimmer water as skimmers
will remove particulates (rather than trapping them as a pre-filter
would do). Spotte confirms this and terms this filtering mechanism
as 'froth flotation'.2.6 Under Gravel Filters (UGF)
Not appropriate for a Reef Tank. Although they will work for 6
months or so, eventually detritus buildup will cause a nitrate
problem. Long term, it's virtually impossible to keep nitrates
below about 40 ppm NO3- which is way too high for corals.2.7 Reverse Flow UGFs
An attempt to solve the detritus buildup problem associated with
normal flow UGFs. It's a good idea that doesn't work well in
practice. This system has problems with uneven water flow due to
channeling within the bottom gravel.
2.8 Trickle Filters
Also known as Wet/Dry Filters. An improvement over UGF and RUGF
filters. Nitrates can be kept low (say, around 5 ppm) with
adequate water changes. It does not seem to be possible to keep
nitrates very low (less than 1 ppm) if a trickle filter is the
sole biological filtration. Those that report less than 1 ppm
normally have adequate live rock, and find that their nitrates
remain low even (and often get lower) when they remove all the
bio-material from their trickle filters (turning them into plain
sumps, useful for holding carbon and as a water reservoir).
2.9 Algae Scrubbers (long)
Summary: The jury is still out, even after several years of
experience. Some species of corals seem to do fine, and occassionaly
even better, in algae scrubed tanks. Other species simply die.
In any case, we still recommend this only for experienced aquarists
who fully understand the risk they are taking. What's included below
is a decent summary of how folks felt a couple of years ago. Most
have softened their view abit since then. Few consider the systems
the ultimate solution...2.10 Live Sand
Of relatively recent interest in the hobby is the use of "live sand".
Live sand consist of small grain (0.5mm-1.0mm) coral sand that is
populated with crustaceans, worms, mollusks and bacteria. It is normally used at a
rate of 10lbs per square foot of bottom area - which yields about a
1" deep covering. Variations from 1/8" to 3"s of covering have been
reported.3.0 Lights
3.1 General Discussion
A rough "rule of thumb" is 4 Watts/gallon with successful tanks
using from 1.5 - 6 Watts/gallon.
3.2 Detail Discussion
For most aquarium lighting applications, the bottom line is
getting the needed intensity and spectrum of light at the lowest
cost while remaining within aesthetic limits.
Annual cost per lumen:
Basically, in fluorescents, the VHO lamps give a higher operating
cost but a lower replacement cost for the same total amount of
light. But it's close, and you should plug in your own numbers to
see what's best for you. If you replace lamps more frequently
then VHO is better, if you pay more for power, NO is better.4.0 Cost Estimates
Here is a rough estimate of what setting up a reef tank may cost.
Two cases are included: a 20g micro-reef and a 70g mini-reef. The
estimates show the min and max for most of the common pieces of
equipment. The estimates assume a standard type of filtration
that is popular today. If a different setup is used, the price
could be more or less. The equipment includes a tank with some
sort of siphon/drain to a sump and then a return pump back to the
tank. A protein skimmer is installed in the sump. This setup is
similar to a typical wet/dry trickle filter except there is no
trickle section with media. This allows the use of simpler, less
expensive sump although a commercial W/D without media could be
used. A trickle media could be utilized at greater cost although
many reefkeepers think it is unnecessary. Keep in mind that
prices sometimes vary geographically. Also, availability may
vary. For example, reasonable Florida live rock will soon no
longer be available (at least not for $2-4/lb).Micro-Reef (20g)
Tank
$ 20/ 140
Glass/
Acrylic.
Stand
0/ 250
Sturdy piece of furniture/
Fancy acrylic stand.
Lights
100/ 300
DIY 60W fluorescent/
70W or 150W MH hood or pendant.
Main Pump
20/ 60
Large powerhead/
Hobby pump.
Sump
10/ 120
A plastic storage container from the hardware store/
A small commercial W/D without media. (A nice DIY acrylic sump can be built for about $40.)
Skimmer
60/ 220
DIY skimmer, power head, air pump/
Small commercial venturi unit with integral pump.
Plumbing
30/ 100
DIY overflow and misc pipes, etc/
Drilled tank or commercial overflow box plus misc pipes, etc.
Live-Rock
140/ 400
35lb case of Fla rock plus shipping/
30lbs of Pacific rock plus shipping.
Water Treatment
100/ 600
DIY mixed-bed DI with carbon prefilter/
TFC RO unit with DI postfilter and automated top-off.
Test Kits
100/ 500
A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits you think you might need.
Salt
10/ 20
One 50g bag, price varies.
Accessories
20/ 200
There are a variety of gadgets you could get. You might want to start with a net or two and maybe a pair of tongs.
Setup Total
$ 610/2910
Mini-Reef (70g)
Tank
$ 140/ 350
Glass/
Acrylic.
Stand
$ 100/ 500
Cheap wood or iron stand/
Fancy acrylic stand.
Lights
$ 200/ 600
DIY 160W fluorescent/
2x150-175 MH hood (possibly with Actinics).
Main Pump
$ 80/ 140
400-600gph, price varies with brand.
Sump
$ 10/ 200
A plastic storage container from the hardware store/
A commercial W/D without media. A nice DIY acrylic sump can be built for about $50.
Skimmer
$ 80/ 450
A DIY skimmer,powerhead,air pump/
A large commercial venturi unit with a large pump driving it.
Plumbing
$ 50/ 150
DIY overflow and misc pipes, etc/
Drilled tank or commercial overflow box plus misc pipes, etc.
Live Rock
$ 460/1200
140lbs Fla rock plus shipping/
110lbs Pacific rock plus shipping.
Water Treatment
$ 100/ 600
DIY mixed-bed DI with carbon prefilter/
TFC RO unit with mixed-bed DI postfilter and automated top-off.
Test Kits
$ 100/ 500
A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits you think you might need.
Salt
$ 20/ 40
Two 50g bags, price varies.
Accessories
$ 40/ 500
There are a variety of gadgets you could get. You might want to start with a net or two and maybe a pair of tongs. You could get wave-makers, circulation pumps and lots of other do-dads.
Chiller
$ 0/ 600
Don't use a chiller, live somewhere cool, keep the tank in the basement, or an adequately air-conditioned room/
A commercial chiller.
Setup Total
$1380/5830
Ongoing Costs