The cycling process starts when ammonia is present in your aquaponic system. Ammonia (chemical formula NH3) is a compound made of nitrogen and hydrogen. Fish produce ammonia most from their feces, urine, and respiration through their gills. Just as our own waste is toxic to us, ammonia is toxic to fish and can kill them. The cycling process converts ammonia to a less toxic form of nitrogen (nitrate) that plants can readily digest.

Cycling with Fish

1. Start fish cycling by adding a few hardy fish to the tank like Goldfish, Tilapia or inexpensive Koi for example. The fish will provide the ammonia source. Do not feed the fish for the first 24 hours. Only lightly feed for the first several days and only what they are willing to consume. Excess feed should always be removed from the tank.
2. Add a nitrifying bacteria starter such as Nite-Out or let the bacteria populate naturally.
3. Perform and record water tests every day to check ammonia, nitrite, and nitrate levels. Ammonia should remain below 3.0 ppm. Nitrites should remain below 1.0 ppm. Nitrates will increase over time.
4. Exchange 1/3 of the tank water if ammonia gets above 3.0 ppm, or nitrites above 1.0ppm. Fish can suffer and may die if levels get higher than these.

Fishless Cycling

1. Cycling with fish can be stressful (on both you and the fish). An alternative is fishless cycling.
2. Add a bacteria starter or let the bacteria arrive naturally.
3. Add a supply of pure ammonia (powder or liquid) until levels are between 2 to 4.0 ppm.
4. Perform water tests daily to detect ammonia, nitrite and nitrate levels.
5. Continue to add ammonia to keep the ammonia levels between 2 to 4.o ppm.
6. Cycling is complete when ammonia and nitrite levels drop below 0.5 ppm with 24 hours. The presence of nitrates indicates cycling is taking place.
7. Stop dosing the system with ammonia and add your fish into the system. Do not feed for the first 24 hours.