The Biological Cycle

One important thing when setting up an aquarium is patience. I know that if this will be your first fish tank, you are just dieing to fill it with all those colorful and beautiful creatures you saw at the fish store, but, if you don't want to be disappointed and lose your fish, wait. Nature's biological process takes from 4 to 6 weeks.

Let me explain the Biological Process... or at least try...

The biological cycle happens when beneficial bacteria breaks down toxic organic compounds into less toxic compounds. Then we can manage these less toxic compounds through weekly water changes. The beneficial bacteria that we need to culture in the aquarium are called Nitrosomonas and Nitrobacter bacteria. Nitrosomonas bacteria break down deadly ammonia to less toxic nitrite. Nitrobacter bacteria then convert nitrite to an even less toxic nitrate.

Nitrogen Cycle

These chemicals can only be detected with test kits. Algae blooms sometimes indicate excessive nitrates. The biological cycle starts when you put 2 or 3 very hardy fish into your new tank. These fish have small amounts of the bacteria in their digestive tract which they will release into the aquarium. Nitrosomonas and Nitrobacter bacteria live in the substrate of your tank. They need oxygen to live. That's why it's important to keep your power heads or air pumps working at all times. They pull air from the water through the gravel giving the bacteria a continuous nitrogen_cyclesupply of oxygen. You can speed up the biological process by adding gravel from an established tank to the new aquarium. I've done this many times with no problems. The bacteria will spread from the old cultured gravel to the new gravel. There are products that can also speed up the biological cycle, like Stress Zyme®, which you add to the aquarium water when you introduce your first fish. Stress Zyme®contains over 300 million beneficial bacteria per teaspoon. To know if your biological cycle is complete, you have to test the water. Get a water test kit that tests for Ammonia, Nitrite, and Nitrate. The first thing that you'll see in a new aquarium is a spike in Ammonia levels a few days after you've added your 2 or 3 hardy fish. Keep testing the water every couple of days and eventually you'll see the Ammonia level drop and the Nitrite level go up. This is a good indication that the biological process is starting.

Test every couple of days and eventually you'll see the Nitrite level drop and the Nitrate level rise. Nitrate is easily managed by changing 10% to 20% of your aquarium water every week. Ammonia starts the whole process. Ammonia comes from fish respiration and decomposing organic wastes such as fish feces and left over food.

You want to add your fish now?

6 or 8 weeks later it's safe to add more fish to the tank. Keep testing your water. Add one or two fish every two weeks until you have the number of fish appropriate to you tank.