Frequently in this hobby we are told to do something without understanding the underlying reason and that is not a good thing. This is why so many people get discouraged with this hobby and leave. Please note: I feel fishless cycling is the ONLY way a tank should be prepared for fish.
The purpose of cycling is to build up the beneficial bacteria in a tank that feed off the waste materials of your fish/inverts. Without these present in great enough numbers, your fish will kill themselves with their own waste. By building up these bacteria prior to adding in fish, you avoid harming your fish. Unlike traditional cycling where a small amount of hearty fish are introduced into a tank, and slowly additional fish are added, fishless cycling (when properly performed) allows for a complete stocking of the tank at once. This is a huge benefit, and one which is often overlooked.
The 2 types of bacteria we are looking to grow convert ammonia (fish waste which is quite toxic) to nitrIte (actually more toxic than ammonia but not as long term damaging), and finally to nitrAte (relatively non-toxic unless allowed to build up to large amounts). So that’s:
ammonia—->nitrIte—>nitrAte
If you add too much, do a Partial water change to reduce the level, if you add too little, dose more. It doesn't need to be exact, but just aim for 3-5ppm. Every couple of days test the ammonia level, when it gets below 1ppm, add more ammonia to keep the level above 1ppm. Normally when I see it get below 1ppm, I dose 3-4ppm back in. Never let it go to zero (until the cycle is finished) or you risk killing off your ammonia to nitrIte bacteria! -Turn your heater up! Aim for 82-85F. This increased temperature speeds up the metabolism of the bacteria which reduces the cycle time.
Make sure the temp is stable before addition of fish.
