If you have a lot of aquatic plants in the tank and they are getting good light, they will use ammonia and stop the cycling process. Basically you don't cycle a heavily planted tank because it will never cycle.
Just add plants, let them grow for a few weeks and then add some fish. Don't add too many fish at a time (except if adding tetras or other schooling fish, add the entire group these at the same time, eg: 20 neon tetras get added at the same time), and wait a few weeks before adding more.
Try to quarantine any new fish for at least 2 (preferably 4) weeks before adding them to an aquariums with fish.
If you use a fertiliser that adds carbon to the water (flourish excell I think it is), stop using it. The carbon is made from glutaraldehyde, which is poisonous to fish and other aquatic organisms.
Anubias and Java fern are slow growing plants and don't need carbon added to the tank. Sword plants will get most of the carbon they need from carbon dioxide (CO2
) that is released from the fish and other organisms in the water, filter bacteria, and from CO2
coming into the water from the air. As a general rule, there is no need to add carbon or CO2
to an aquarium, especially if you have slow growing plants.
Some power filters have Zeolite (Ammogon) in their filter pads and this removes ammonia from the water. Zeolite is a small white granulated substance. If you have this in the filter pad, you can cut the filter pad open at one end and tip the Zeolite out and throw it away. Then put the filter pad back in the filter and let the filter run.
Zeolite (Ammogon) should not be used in aquariums and is a gimmick used to get your money. Just have sponges in a filter.