You should know if your tap water is hard or soft so you can adjust it if necessary for your aquarium. Hard water has a high content of certain minerals -- magnesium, calcium and iron salts -- and soft water does not.
The
biggest concern with tap water, though, is what the city water department puts
in it. Most municipal water companies add chlorine or chloramine to the water
to kill certain bacteria that are harmful to people. Unfortunately, these
chemicals are themselves harmful to fish and must be removed from the water.
Every
pet store has a selection of chemicals that will easily dechlorinate the water.
For dealing with chloramine, however, you need something a little different. Chloramine
is a combination of chlorine and ammonia. When a normal dechlorinator is used
at double the recommended amount, it will break the bond between these two
compounds, neutralizing the chlorine but releasing the ammonia. The added
ammonia may be more than the nitrifying bacteria in your tank's biological
filter can handle.
The
only way to handle this problem is to use a one-step water conditioner designed
to handle chloramine. This product will break the bond between chlorine and
ammonia and neutralize both.
