tanks should have 0 ammonia and nitrite. I'm guessing you're not completely cycled yet.
Right now, don't put any chemicals in your tank and do large daily water changes. Use a dechlorinator, such as Prime, when you do your water changes if you're on city water.
If it is a new tank, don't clean your filters, or replace anything in your filters. Let them build up beneficial bacteria. You may even want to try something like Stability to help seed the tank with bacteria. When you do feel the need to clean your filters, use tank water, not tap, so the chlorine doesn't kill the bacteria.
Again, if the tank is new and not cycled, I'd go light on the feeding as well. Any extra food or waste in the water will give off more ammonia/nitrite.
Hope that helps.