What to Test for in an Aquarium? By Lev Ingman
In all fish tanks, Ammonia, Nitrite, Nitrate, and PH should be tested for. Ammonia and Nitrite should always be 0. In tanks that lack invertebrates Nitrates are tolerable to an extent. In other words, most fish do not care about a moderate amount of nitrates in their water. Certain fish will even tolerate and thrive in water with very high nitrates, but in the vast majority of cases you should try and keep your nitrates under 60 ppm. Discus is one example of a fish that needs to be kept under low nitrate conditions in order to look their best. Some people say that Nitrates do not affect fish, and if you consider being alive as the bottom line, then yes Nitrates will not kill your fish. However, your fish will look significantly better in a tank with low levels of nitrate.
In a salt water tank, PH should be kept as close to 8.3 as possible. In a freshwater fish tank, you want to mimic the PH of the environment where those fish came from. Discus prefer lower PH, and African cichlids prefer higher Ph. Most captive raised community fish will tolerate a wide range of PH.
In a salt-water tank, you should also check for salinity and keep it between 1.019-1.025. If you have only fish and no invertebrates keep the salinity closer to 1.019 and if you have a tank stocked full of corals you should keep it closer to 1.025.
PH in a salt-water fish tank tends to decrease because acids are released as a result of various metabolic processes in your tank. In order to reduce the fluctuation of PH in your tank, you must add KH buffer. Keep your KH between 8-12 drops and you should see stabilization in your PH. This is especially important in a reef tank because these tanks are more sensitive to PH fluctuation.
Phosphates- In a reef tank it is important to check your phosphate levels, and remove them using a good Phosphate remover.
Magnesium– this is the most overlooked element that is important in a reef tank. You should keep your levels of magnesium as close to 1400ppm as possible because magnesium is very important in ensuring calcium and alkalinity.