To cycle a new aquarium in preparation for the addition of fish by using fishfood to generate ammonia for 1st stage bacteria to begin the nitrogen cycle.
This method is kinder to your fish than using fish to cycle. Try it, you’ll be very surprised, and encouraged by the results.
a) Once your aquarium is all setup and running, put a couple of decent size flakes of fish food into the aquarium.
b) Give it a couple of days and then perform a water test for the presence of ammonia.
c) If you detect no ammonia or if the your ammonia reading is below 3 Parts Per Million (3ppm) drop a few more decent size flakes into the water.
d) Test every other day adding a few more decent sized flakes if the ammonia reading is below 3ppm
e) Once you are about one week into the process, begin to do tests for Nitrites in the water. If you detect nitrites in the water then this means the first batch of good bacteria has begun feeding on the ammonia and is turning it into nitrites. (a good thing)
f) Carry on with testing for nitrites and ammonia on every other day and putting a large flake or so into the tank whenever ammonia reading falls lower than 3ppm. Eventually the nitrite level will start to fall and now you can begin to do water tests for Nitrates. Once you see nitrates this means the second colony of good bacteria has set up shop and is feeding nicely on the nitrites to convert them to the less toxic nitrates. Once Ammonia and Nitrite levels fall to zero, and remain there for some days without fluctuations, your cycle is pretty much done, and you should do a mid to large water change with a gravel vacuum just over the top layer for now to remove any loose food on the surface.
Usually if you’ve seen this ‘balance’ with zero ammonia and nitrites for two or three days, then the aquarium tank is now cycled, and you can likely look at adding in the fish.
First off ensure you’ve vacuumed as much fish waste as you can out of the tank, any fish you add will add ammonia anyway, but just make sure if vacuuming gravel that you do not over-vacuum and clean too much gravel, try to leave at least 50% for now untouched and just the surface cleaned only.
When adding fish however, don’t rush the process, introduce them gradually and leave at least a week between each introduction group of fish to give the bacteria colonies time to adjust and multiply to deal with increase in aquariums bio-load. Also, please don’t make the common mistake of overstocking your aquarium, think about how big your fish WILL be at adult size, not how they look now, that changes rapidly, so think with the fishes best interest and health in mind.
Patience IS everything, and patience now could save many fish.
Enjoy fishkeeping as I am so far, its amazing.