&ItemNoChlorine – Quick Reference
Chlorine is very toxic and is not tolerated at any level! Always use dechlorinator. Many brands are available: SeaChem, Tropical Science, AquaLife Complete (The best), Kordon makes great products. Many hobbyists swear by Start Right.
Chlorine provides the same service in a fish tank as it does in the municipal water system – it kills everything. Gills are a delicate arrangement of high surface area tissue with counter-current blood flow through which fish absorb oxygen from the water. Anything that even slightly adversely affects the gills seriously affects the fish’s ability to survive. Chlorine burns delicate gill tissue and quickly leads to death. Biological filtration is also adversely affected by chlorine and may require reseeding with bacteria cultures.
Never add water to any aquarium or pond without first adding dechlorinator. It is possible to add tap water straight to an existing tank without killing your livestock if the chlorine binds immediately with organics in the tank. Most hobbyists will testify that they have done so and not lost fish. This practice, without question, is irresponsible. Taking a chance of killing everything to save time or a few pennies makes no sense.
Modern water conditioners and dechlorinators do much more than simply remove toxic chlorine. They add slime coat protection to fish, reduce stress, reduce susceptibility to disease, and bind harmful compounds. The additional benefits make them a good choice even for well water or reverse osmosis water.