Beginning Saltwater -- Long-term Success
Over the course of the first 4 to 6 weeks your tank will demonstrate the typical cycling process (which is described in detail the BEGINNER FAQ). During this critical time, you should carefully watch the ammonia and nitrites in the tank. If the fish look stressed (darting around the tank, gasping for air, or not moving at all), a partial water change might be in order. If the fish look really bad, they may have to be moved to another tank or storage location until the toxicity of the tank is reduced. You should always keep salt mix and dechlorinated water on hand for impromptu water changes.
Along with monitoring ammonia and nitrites, you should keep a careful eye on the pH (you should always watch the pH, not just during the cycling process). The pH will tend to fall over time and needs to raised. The easiest way to raise the pH is through additions of sodium bicarbonate (i.e., baking soda). Mix a tablespoon or so of baking soda in a cup of dechlorinated water and slowly add it to the tank. Slowly means over the course of an hour or two. Baking soda will cause a short term drop in the pH, but will bring the pH to 8.2 over time.
As time marches on, water will evaporate from the tank and need to be replenished. The water that evaporates is freshwater and needs to be replaced with freshwater. You should never use saltwater for makeup water (unless you want to increase the salinity of the tank).
As the tank matures, algae will start to grow (usually around week 2 or 3). Typically brown algae, otherwise known as diatoms, will be the first algae that shows up in the tank. Brown algae will usually cover everything in the tank and need to be cleaned every week or so. With time green algae should overtake the diatoms and the brown algae will disappear all together. If it doesn't, there might not be enough light for the green algae to out-compete the diatoms.
After the tank completes cycling, it will be time for your first major water change. Although the amount of water you change is really up to you, it should be a significant portion of the water. Something like 40 to 50%, with 100% of the water not being uncommon. When changing the water, the gravel should also be cleaned. There are many commercially available gravel cleaners on the market.
The chemistry of the change water should be as close to the tank's water as possible. The pH should be within 0.2 and the temperature should be within 1-2 degrees. It is better to have the change water warmer than cooler (imagine the shock of a cold shower and you will know how your fish will react to cooler change water).
After the first water change you should establish a regular maintenance schedule. Something like monthly water changes, weekly algae scrapings, and bi-weekly feedings are normal.
A note on nutrition. Saltwater fish need varied diets. Constantly feeding your fish flake food may provide it with all the necessary vitamins and minerals, but this may ultimately cause a nutrition deficiency of sorts. Alternating between cut up shrimp and clam, flake food and frozen/live brine shrimp makes a good combination. Herbivorous fish, like Yellow Tangs, also like romaine lettuce or Nori (an algae regularly sold at oriental markets) on a regular basis.
Most equipment used in freshwater can be used in a saltwater system, with a few exceptions. You should start by replacing your gravel with some sort of calcerous material. Examples include crushed coral, dolomite and argonite. Using these types of substrate tend to help buffer the water and produce a more stable environment. Next, you need to check all your equipment for anything metal. Saltwater will rust anything except the highest grade stainless steel. There are stainless steels on the market which will rust when exposed to saltwater. Needless to say, you need to replace or get rid of anything made of metal.
The filtration system used in your freshwater system will usually be adequate for a saltwater system. However, you can use this opportunity to upgrade or change filtration mechanisms. Also, which ever type of filtration system you are using, you should add some sort of extra water circulation to the tank. Saltwater has a lower dissolved oxygen content than freshwater, so you need to keep the water in the tank moving. Actually, it needs to do more than move. You need to disrupt the surface of the water to maximize oxygen transfer with the atmosphere.
The lighting you used for you freshwater system should also work for a fish-only saltwater tank. However, if you want to keep invertebrates, you will need to upgrade (more that just your lighting).
One part of a freshwater system that needs to be replaced is the food. Marine fish need varied diets. You need to supply your fish with a combination of fresh, frozen and live food. Flake food, although adequate, should not be the major portion of your fish's diet.
Finally, when you are ready to make the switch to saltwater, you really should replace all the water in your system. It is best to start with nitrate free water to minimize the potential for algae problems. Also, many people think that adding salt to a cycled freshwater tank will yield a cycled saltwater tank. Experience have shown this is not true. Saltwater nitrifying bacteria are different than freshwater nitrifying bacteria, so they must be cultured from scratch. As a note, nitrifying bacteria seem to be pH and temperature sensitive. So moving some gravel from a warm saltwater tank (~85F/24C) to a temperate saltwater tank (72F/21C) will shock the bacteria enough to nullify any advantage from using the gravel (e.g., to shorten the cycle time).
Source water for saltwater tanks is also very important. Although the water authority says that tap water is fit for human consumption, it may not be fit for your fish. Tap water typically contains chlorine and chloramine, which will kill your fish. Although these will have an immediate effect on your fish, there are usually other contaminates in tap water which need time to affect the tank. In particular, phosphates will cause massive growths of hair algae and potentially cyanobacteria outbreaks (red slime algae). Without good quality source water, your tank will not be the continuous joy you hoped it would be.
The best water purifiers on the market are reverse osmosis units. These, coupled with de-ionizing resins, produce water which is 98% pure. If the price of a RO/DI combination is too much, then you can always use distilled water (not spring water). However, distilled water may have been stored in copper containers which will kill invertebrates.
Before you start your saltwater tank, find a good store near you. Good stores will have knowledgeable staff and exhibit a general concern about the care of the animals. If the store has few saltwater tanks, with a lot of sick or dying fish, don't buy any fish there, even if they look healthy.
The last point about keeping saltwater fish is to read, read, read. The FAQ is no substitution for reading a good book. Some of the best are The Marine Aquarium Handbook by Martin Moe, The Book of the Marine Aquarium distributed by Tetra Press, and The Marine Aquarium Reference also by Martin Moe. Also, don't be afraid to post to *.aquaria. Just don't forget to include all the importance specifications (e.g., ammonia, nitrite, nitrate, pH, temperature, how old the tank is, how big the tank is, and what the inhabitants are). Happy fish keeping.
30 gallon tank $30 Custom Hood $20 Custom Stand $30 1 Phillips Ultralume $11 1 Coralife Actinic Blue $15 Wizard Electronic Ballast $28 (now $49 including the endcaps) DIY w/d filter $30 Amiracle Prefilter $50 Eheim 1250 $69 DIY 30" Air-driven skimmer $50 Hagen 801 powerhead $22 Tetra Luft G Airpump $20 Hagen 301 (circulation) $15 Ebo Jaeger 100W heater $16 20 lbs dolomite $8 Misc. Rocks $15 2 Domino Damsels $10 Total $439.00
End of Saltwater Beginner FAQ.