Conditioning water

You should NEVER add the fish immediately after filling your aquarium. Allow the
water time to stabilize. The water will have some amounts of toxins in it from chemical
treatments etc and this can be very harmful for the fish. Thus the water needs to be
neutralized first. Any dissolved gases in the water will escape in a few days, and the pH
of the water will also stabilize.
Tap water is not the natural habitat of fish. Tap water usually contains high amounts of
chlorine and other disinfectants. These will harm the fish, the plants and other
microorganisms that need to grow in the aquarium. There are three basic methods to
dechlorinate water. Aeration of water will diffuse chlorine into the air. This can be
achieved by filtering the water for 24 hours. Using activated carbons is another way of
getting rid of the chlorine. Lastly, adding sodium thiosulfate to water instantly inactivates
chlorine. Sodium thiosulfate also helps in getting rid of traces of ammonia. When adding
the water preparation chemical it is important that you follow the dosing instructions
carefully.
Adding aquarium salt or kosher salt is also recommended if you are going to keep fish
that tolerate salt as it reduce the risk for disease in your aquarium. Some tropical fish do
not tolerate salt in the water and you should therefore research if the types of fish you
intend to keep in your aquarium tolerate salt or not.
If your fish species tolerate salt, 1 tablespoon of salt for every 5 gallons/ 20 L of water is
usually a good rule of thumb. Some species will however only tolerate lower
concentrations of salt. The most important thing to keep in mind while adding salt is the
concentration of salt in water. As evaporation takes place, the salt in the water remains
the same. Salt does not evaporate. So, while changing water, only the salt that has been
removed should be replaced.
One more reason to research the species you intend to buy is to help you decide on the
pH value of your water. Neutral pH is 7.0. Usually, tropical fish can survive in a wide
range of pH. A pH of 6.4 to 7.9 is an acceptable range for a wide variety of fish. Knowing
the pH value of your tap water is a definite advantage. Your geographical location
influences the pH value of the water.
Before attempting to change the pH, there are certain things to be considered. Even if you
have researched the optimum pH for your favorite fish, you need to assess if you really
have to change the existing pH for the fish to survive and thrive. Mostly, the fish you
have are bought from an aquarium. So, they are used to a pH level that might be different
from the pH levels that are natural for them. A STABLE pH is more important than
reaching exact values. Changing the pH values will also change the toxicity of nitrite and
ammonia.