What Cycling Means
Cycling establishes microbial communities that process ammonia produced by livestock and decomposing organic material. A new tank is not biologically mature simply because the water looks clear.
Fishless Cycling
A controlled ammonia source can be used to establish the biofilter before livestock are added. Test regularly and follow the cycling method carefully.
What to Test
Track ammonia and nitrite as the biofilter develops, followed by nitrate. The system should be able to process the intended waste load without detectable ammonia or nitrite.
Do Not Rush Livestock
Adding sensitive fish before the biofilter is ready exposes them to toxic nitrogen compounds. Patience at this stage prevents many avoidable problems.
After the Cycle
The biofilter must still be maintained. Avoid suddenly adding far more livestock than the system can support, and continue routine testing and water changes.