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Must Know Information for a New Aquarium

Tony Christmas 1971

By Tony Griffitts

When starting a new aquarium there are some very important things you need to know before adding fish to the aquarium.  Having a large filter on your aquarium will not keep your fish alive during the first month the fish are in the aquarium.  Bacteria known as Nitrosospira and Nitrospira (read about Dr. Timothy A. Hovanec's discovery at is what the aquarium needs in order to oxidize ammonia and nitrite that gets created by the fish and other aquarium life.  A filter cannot oxidize ammonia and nitrite without Nitrosopira and Nitrospira bacteria.

When you start a new aquarium, it takes about 35 days to develop enough bacteria in your aquarium to keep your ammonia and nitrite levels in the safe range.  Some ways to speed up this process is to add gravel from an established aquarium, and/or add a bacteria booster.  This will introduce beneficial bacteria to the aquarium.  Since the beneficial bacteria live on the surface area in an aquarium, transferring water from an established aquarium will only add phosphate and nitrate.  This is not recommend unless you are moving fish from an establish aquarium where you may be concerned about the fish getting pH shock if they are introduced to all new water.

Having an ammonia and nitrite test kit on hand is highly recommended when starting a new aquarium.  Ammonia levels will normally peak around two (2) weeks after adding the first fish, and nitrite levels will peak around three (3) weeks after adding fish.

During the first month you should keep the fish population very low.  The more fish you start with the higher your ammonia and nitrite levels will go.  Also keep your feedings light and only once every other day.  Your fish will not starve to death.

Many fish will live through the high ammonia levels during the first month, but it is the nitrite you really need to watch out for.  Nitrite kills fish more often than ammonia.  If your ammonia or nitrite levels get very high you can do a 90% water change to lower the concentration of ammonia or nitrite.  After you have done the water change, test the water again for ammonia or nitrite, and do another water change if necessary. Keep testing your water every other day until you notice the ammonia or nitrite levels are going down without a water change.

You can see symptoms in your fish of ammonia and nitrite poisoning.  If your fish are at the top of the aquarium breathing heavily or laying on the bottom not being very active, you should check your ammonia and nitrite levels immediately.

Once your ammonia and nitrite readings are at 0 ppm (parts per million) you can then increase feedings.  While you increase your feedings make sure you test every few days to make sure your ammonia and nitrite stay at 0 ppm.

Published - 2003

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