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Thanks to the encouragement of other enthusiasts, some here at Fish Profiles, after one year with a low-light, planted tank I invested in a high light planted tank. I planted it this week-end and was getting ready today to introduce CO2 for the first time. I was shocked to discover via the Pinpoint CO2 Controller that I have a ph of about 4.0 (more like 3.99 but I don't like to brag). I retested calibration and it is calibrated correctly. I never expected this having always used standard test kits and having received readings fluctuating from the lightest color (which I assumed was around 6.0) to 7.6. My KH is 1 and GH is 1-2.

So here is where I covet expert advice. I have a tank full of a variety of plants that should do well in moderate to high light (260W in 90gal) and now I do not dare add CO2 which would lower the ph even more. I don't want to kill the fish (Congo Tetras, SAE, Oto's, Bristlenose Pleco, Upside Down Cat, Praecox Rainbow).

Questions:
1) Is my assumption right that I should raise the ph somewhere into the 6's so that I can start using CO2? Also assuming here that keeping CO2 out of the tank is a good idea for now. Thoughts?
2) What is the best way to slowly raise KH and GH so that I can get the ph up there? I've read lots of contradictory things. I do have some crushed coral on hand as well as potassium sulfate and magnesium sulfate. Which is best and how much? I'll get something else if necessary.
3) In the interim, any advice for keeping the plants healthy while the ph is being raised? I'm lowering the number of hours with light. Is it Ok to dose ferts?

I'm flummoxed,

Hi,
I got your PM and came right over. WOW! 4.0pH.
I gotta say that I'm really skeptical of that reading.
I've been using a Pinpoint monitor for nearly 10 years
now and other than when the battery is weak, I've never
had readings like that.

My first inclinations are that you have some how managed
to miss calibrate the meter. Perhaps you used the wrong
standard for the setting of the calibration screw.
The next is to get an independent verification of that
reading. Take some fresh tank water, in a clean container,
to a nearby LFS and ask them to test the pH.
My next is to question your water source. What is the
pH out of the tap, and 24 hours later when the sample has
had a chance to degas?

From your comments, the tank has been setup and running
for a while now and that all you did was to increase the
lighting and add more plants. Non of that would shift the
pH. If it truly is 4.0 then any changes you do would have
to be done very very slowly so you don't shock the fish and
other critters in the tank. Your water is very soft.
To increase the KH of the tank and not affect anything else
you would add plain old baking soda such as Arm & Hammer
to the tank. Don't add so much that you change the pH more
than 2 points every other week. The fish have to acclimate
to the shift. As you add the baking soda, the pH will
increase toward 7.0. I would be safe and move it 1 point
over a two week period.

Adding any carbonate to the tank will increase the GH
of the tank. I would use crushed dolomite or crushed
oyster shells, or crushed limestone, instead of
crushed coral.
Crushed coral is straight Calcium Carbonate (CaCO3) with
no impurities. But, you want the impurities such as
Manganese Carbonate (MgCO3) and others as well. You will
get that with the crushed dolomite, crushed limestone, or
crushed oyster shells.
I would not just dump a handful or two of the carbonate
into the tank as there is no way to say that one handful
will equal x number of points on the GH scale. It might
be better to place the carbonate in a mesh container
(bag) and put it in the filter or stick an extra HOB
filter on the tank with just the carbonate in it and
monitor the GH then regulate the flow through it to
maintain a specific GH.
Again, because your water is so soft, I would make the
changes very slowly so you don't stress the fish, giving
them time to acclimate between shifts.

Until you get the KH up at to least 3 and more preferably
around a 4, I would not turn on the CO2. With the
KH as low as it is, just "cracking" the valve would cause
a large swing in the pH even further downward. Heck none
of the CO2 charts that plot pH vs KH to determine the
CO2 saturation go any lower than a pH of 6. God only knows
what would happen if you were to begin injecting CO2 at
this point.

Hope this helps...

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

This was very helpful, Frank. Thank you.

Re. calibration: Last night, I had just calibrated my ph controller right before sticking it in the tank. When I got a reading as low as 3.9, I put the probe back in the 7.0 calibrating solution and the meter went right back to 7.0 right away. I also have a 10 gallon tank with crushed coral in the filter and the store-bought ph test read about 6.8. I stuck the probe in a sample of that water and it read 6.7 Then probe was back in the planted tank and dropped to 3.9.

To top it off, my tap water came in last night at ph of 8.3. I called the local water district this morning and found out that the lake where our water comes from has notably soft water. Because we live in an area with historic and other old homes that might still have lead pipes, they add soda ash which drastically increases the ph but does little for the kh or gh. Further research on the net tells me that, once this type of water reaches the light, it loses its alkalinity. This does explain a lot.

They've invited me to bring my ph meter over and check the calibration which I will do soon as I can.

While I work on getting some semblance of order with the water, any suggestions on how to care for the plants? Today, I went with 7 hours of full lights (instead of 11). No CO2. I have held off starting other ferts too - afraid to activate algae without the CO2 in there. Would appreciate advice there too. Thanks!

Hi,
First things first. I think you can resolve the water
supply problem by getting a plastic 55G drum to store your
water in. That amount of water should allow you to do
just about any size water change you feel is necessary,
when it is necessary. Put an air stone in the drum for
circulation, and a lid over the top to keep out dirt, etc.
After filling the drum, run the air stone, for 24 hours and
then test it. Add baking soda as necessary to bring the
KH up to four. You could also run a canister filter filled
with one of the crushed carbonates I mentioned to bring
the GH up as well. In other words store your water and
pretreat it.

It might be interesting to measure the lake that is the
source of your water to see what it's values are.

I'd run the lights for 10 hours. After running for a year
with those fish, plants, and filtration, that is a mature
seasoned tank. There should be enough detritus in the
gravel to provide the nutrients necessary for plant
growth.

You might want to read the following as when you do start
to inject CO2, the plants could easily outstrip the tank
of nutrients making fertilization a necessity.

http://www.csd.net/~cgadd/aqua/art_plant_nutrient.htm

http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

http://www.thekrib.com/Plants/Fertilizer/pmdd-tim.html

http://www.barrreport.com/estimative-index/62-estimative-index-dosing-no-need-test-kits.html

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Thanks again, Frank. I will have to pass on the barrel full of degassed water due to aesthetics (ie. don't want my very tolerant wife to get turned off by my sometimes all-consuming hobby. Space would be an issue too. I think I'll try 5-10% daily water changes for awhile. The tap ph is reading at 8.6 today while the kh is about 2 and the gh 1-2. I'm going to find one of the items you suggested for raising Gh and Kh as well. I'm going with 7 hours of light now but I'll bump it up an hour every few days during the interim and monitor the effects.

Just wanted to update my post from last month and share my learning experience. After cross-calibration, I determined that my ph monitor was correct and that my natural ph was indeed about 3.9-4.0 and, due to soda ash in the water, any new tap water added would start with a ph of 8.0-9.0 for part of one day and would eventually drop back to highly acidic levels.

I began adding one teaspoon of baking soda per day and measuring Kh daily. Each teaspoon would raise the ph about .6 and the ph would drop about .3 in the next 24 hours. The fish did not seem bothered by this at all. It took about three weeks to raise the Kh to about 4 and, as the ph closed in on 7.0, the ph fluctuations with each additional teaspoon of Baking Soda were smaller. I added crushed coral to my canister filter but the Gh readings on the test kit I have are so ambiguous, I am not sure but I think the Gh remains 1-2. I will change to crushed limetone at some point.

I am running CO2 with lights on (9 hours per day) now. The tank typically fluctuates between a Ph of 7.0-7.5 with CO2 off/on respectively. I have been conservative with ferts due to smaller water changes (as I only seem to have time to do about one water change per week these days). I have limited water changes to 20% at a time to avoid large ph swings. Now, when I add 20% tap water, the Ph swings up only to about 7.6 and down to 6.8 the next day. No fish deaths and fish have never seemed stressed as long as I run my HOB when the lights are out. Some plants have done great, others have not but I think those have needed more lights than the 2.8w/gal that I currently have.

Thanks Frank and this site for helping me figure out what to do. Hope this helps someone in the future with very soft water, low ph, and soda ash in the water that makes for temporary high ph levels and major fluctuations -

Hi,
We all thank you for the update. It looks like you are
getting a handle on the problem and have created a schedule
that works for you.

You might consider taking the carbonate out of the
filter and using the carbonate as your substrate
and also in your hard-scape. IE: use crushed limestone,
coral, or dolomite as your substrate, and use pieces
of limestone to build your caves or cliffs (whatever)
for the fish to swim into and out of.
Keep in mind that crushed
coral is primarily Calcium Carbonate(CaCO3) with little,
if any impurities such as magnesium and others. The
Limestone, or Dolomite do contain those other necessary
impurities and would be better than the coral.

Doing small water changes 20% or less is the correct way
(as you discovered) to prevent the large pH swings during
a water change.

Here, I run my CO2 24/7/365. How are you turning it off
and on? Using a controller, in combination with a pH
probe, would eliminate the over night, lights out, swings
of pH.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Thanks, Frank. I will consider moving from coral to limestone soon. I was a little reluctant to put either in the substrate in case it made the Ph too high and then I'd have a hard time getting it all out. However, I can see that this might be a good idea.

I am currently running my CO2 on a timer that goes off and on with the lights (on when on, off when off). When the lights go off and the CO2 goes off, my two HOB's turn on. I set it up this way based on one experience and an assumption based on readings I'd done. Let me know if this is inaccurate: I thought plants took in CO2 when lights are on and emitted Oxygen and then the opposite happened at night when plants take in Oxygen and emit C02. The second morning after initiating a planted tank, I found the fish all gasping at the surface and that made me turn on the HOB's to get some Oxygen into the water. I assumed that, at night, the plants might hog the Oxygen and leave little for the fish - thus my current plan. Let me know about this. Also, I do have my PH Controller set to shut off CO2 at a certain point but the PH never drops that far -

Hi,
Well you may want to change a couple of things.

First, the HOB's. They should run 24/7. When you cut them
off each day, the bacteria in them will die off and the
water would turn "stale." When they come back on, all that
"stale" water, and dead bacteria, is flushed into the
tank with the fish. That means the filter has to begin
creating the Nitrogen Cycle all over again. Depending
upon the size of the filter and amount of water the
colonies will be either be weakened by die off or outright
killed off with by 12 hours of no circulation.
If running the HOB's changes the pH (generally upward)
then I would suggest finding some way so that the return
water does not rile the surface which breaks the surface
tension and allows the CO2 to equalize with the atmosphere.
To compensate for the riled surface and the CO2 exchange
you would have to increase the amount of CO2 injected.
This, in turn, could cause the fish distress.

Since you have a controller, I'd set that to maintain the
pH at a desired level - which comes to the next part,
what is the KH? Glance at the charts and find the
intersection of the KH and pH, that will tell you the
CO2 concentration. With a KH of 4, I find it hard to
believe that your fish are lacking O2 during the night.
Either one of your readings is way off base (KH or pH)
or your tank is really crowded with fish. Usually one
has to really "work" to get to that point.

The usual "excuse" for not running the CO2 24/7 is to
conserve the gas to make a tank of it last longer.
You are correct in that you don't need to inject it 24/7.
I do, because I don't have the equipment to turn it off
and on. I use a bubble counter and the needle valve on
the regulator. I set it so that I have the desired pH
and the desired CO2 saturation. If I were to turn off the
needle valve at night, I'd wind up spending half the next
day trying to adjust the valve back to where it was the
day before (the correct values for pH & CO2). I keep the
tank lightly stocked, and have never had any troubles with
too high a CO2 saturation (fish gasping at the surface in
the morning.) I'd probably set the controller to shut off
the CO2 sooner and maintain the desired level all the time
instead of a timer to shut it off.

Try to maintain a KH of 4. That's a good spot to target.
Do that by adding the baking soda as it will not affect
the GH, only the pH. When you have the tank holding at
a KH of 4, then start adjusting the CO2 and the pH.
Try to keep the CO2 saturation somewhere between 15mg/l
and 30 mg/l. To do that set the controller to hold the
pH at whatever value (with the KH) gives you somewhere
in the middle of the two saturation values.
Many run their tanks at a saturation of 30mg/l
while others stick around 20-25. 15mg/l is about
the lowest you would want to go. I have found with my
tank that the KH slowly decreases and that I have to
add additional baking soda every three days to maintain
the KH at 4. You may have to do the same.


Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

About running the filters just at night. You would be better off getting a powerhead and setting that on a timer to come on after the lights go off. That way you do not have to deal with stagnate water.

I do not have a pH controller with my set up. I have mine set to run when the lights come one and go off with the lights. I have been doing this for the last 3-4 years now without any major issues.

55G Planted tank thread
19G Container Pond
[IMG]http://i4.photobucket.com/albums/y118/Wingsdlc/Ric

Hi,
Something like this:
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4585+15955&pcatid=15955

Might be the ideal thing that Wings is talking about.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Great information, Frank. I'm going to try to digest it all. I can see that I need to do this differently - Rick

Thanks, Wings and Frank. I will likely get a powerhead and shut off the HOB's

Hi,
I guess I'm missing something...Why are you turning off
the HOB's at night? Theoretically, they should run 24/7.
That way the bacteria in them continue to function, and the
currents they generate in the tank will prevent stagnation
in the tank. You said your fish were gasping at the
surface of the tank in the mornings... Part of that is
because of lack of circulation, and lack of
surface exchange between the tank and the atmosphere most
of which could be attributed to the HOB's being turned off
at night.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Frank,

You have seemed to get things mixed up. The HOB filters are coming on at night to add aeration. They are then set to go off during the day so that there isn't a huge loss of CO2.

I was thinking a pump something more like this. That way you could run an air line to it.
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4585+4609&pcatid=4609

55G Planted tank thread
19G Container Pond
[IMG]http://i4.photobucket.com/albums/y118/Wingsdlc/Ric

I am guessing that a canister filter is also being use as the normal filtration 24/7?

55G Planted tank thread
19G Container Pond
[IMG]http://i4.photobucket.com/albums/y118/Wingsdlc/Ric

Hi,
Yup Wings, ur right, not enough coffee in the mornings.
Despite having my days and nights confused, I was trying
to point out that filters are not designed to be turned
on and off, but rather run 24/7. If the HOBs are being
used strictly for circulation, then there should not be
any filter media in the boxes. They should be empty and
used only for circulation.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

I agree with you about not using any filter material. Will the filters kick on and prime using a timer? I don't think mine would but mine are pretty old.

55G Planted tank thread
19G Container Pond
[IMG]http://i4.photobucket.com/albums/y118/Wingsdlc/Ric

HI,
I might not have been really clear when I said that
they should be empty. It was a continuation of the
previous sentence, where I said there should be no
media (carbon, filter floss, sponge, etc.) in them.
They should have water in them I would keep them
running 24/7, for circulation anyway.

I like the new pumps that have come out, mainly for
reef keeping, that have the motor external to the
tank and the impeller mounted opposite to it, inside
the tank. With one of them, he could do away with the
HOBs completely and use a canister filter.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--