How to Create Good Bacteria in Fish Tanks

Good bacteria reduces the amount of ammonia in fish tanks, which keeps the nitrite and nitrate levels at the proper level. This good bacteria essentially keeps your fish alive, but does not exist in new aquariums. You must grow the bacteria before adding new fish and monitor its growth through the nitrate cycle.

Difficulty: Moderate

Instructions

Things You'll Need:

• Nitrate, nitrite and ammonia tests

Create Good Bacteria in New Fish Tanks

1. Use "dirty" filter cartridges or used components from a friend's tank or fish store. These used filters already contain good bacteria, which gives your tank a head start in growing its own. Keep the cartridges wet until you place them in the tank, so the bacteria don't die. When you buy a new tank, you can sometimes buy water as well, which already contains the elements needed to grow bacteria.

2. Place live plants in the tank immediately, even if you are not ready to add fish. This starts the bacteria growth. In general, you should set your tank up completely and run it for about week before adding fish. It takes anywhere from 1 to 3 weeks to create enough good bacteria to sustain life in fish tanks.

3. Let the aquarium cycle completely through once before adding your main fish. The ammonia and nitrite levels will spike and then drop to zero. Once they are consistently tested at zero, your tank is ready to add fish.

4. Add fish slowly. Start by adding one or two fish per week for about 4 to 6 weeks. Feed the fish sparingly at first and monitor the ammonia and nitrate levels. If there is a spike in levels, change only 20 percent of the water to regulate the level. Try to change the water as little as possible as your tank stabilizes.

Increase Good Bacteria in Working Fish Tanks

5. Add additional gravel or other substrate to the tank. Also, add lava and bio-rings to your filter. This gives the bacteria a place to live. It takes about 3 weeks to create more bacteria.

6. Only change 20 percent of the water at a time. This gives plenty of time for good bacteria to build up. You should change and clean the tank about once every 2 weeks.

7. Keep your filters on when changing the water and cleaning. If you have upper filters that will be out of water, you may want to place the cartridges or other media (foam, tube, bio-wheel) in the water. Turning off the filter or leaving pieces out of water for too long may kill the bacteria.

Tips & Warnings

• You can cycle your aquarium with fish, but they will most likely die. Simply buy hearty fish like black skirt tetras. Add the fish immediately, but feed them sparingly. Monitor the aquarium as it goes through its nitrate cycle.