How and Why to do water changes.

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If your ammonia, nitrite, or nitrate levels are too high, then you need to do a water change. I like doing 50% water changes. By doing a 50% water change, you can see a difference that you have made. And simple math tells you that doing a 50% water change will reduce your levels of ammonia, nitrite, nitrate, or other toxin levels by 50%.

Water changes are the best way to quickly get water parameters back to where they should be. Too many times a new fish keeper will ignore this simple task, only to let his fish get worse.

See Nitrogen Cycle.