Tap water

Hobbyists usually choose contamination by organisms to cope with the water conditions offered by tap water. When water levels lower in the aquarium, tap water can then be directly added to an aquarium after a water change in accordance with tempered water. Many aquarists treat the water with a water conditioner to bind the heavy metals contained therein and to neutralize any existing chlorine.

Only in water very strongly contaminated with heavy metals or herbicides is it necessary to filter with a carbonite filter. In general, tap water can be changed so that any desired value of water can be achieved. It can be very hard to put tap water through reverse osmosis or through a mixed bed filter to lower the hardness. Brackish or salt-water conditions are achieved by the addition of special salt mixtures.