Feeding live feeders is a Risky diet. They can introduce parasites and disease into ur system. Even after many weeks of quarantine the feeder may still have unnoticeable Parasites. That can be passed to the fish that eats the feeder.
theres your problem. Ammonia always has to be zero. Start doing some massive daily water changes to flush your system and make you learn to cycle your tank properly.
Oh !!!!! I thought 0.5 is fine.. But you should know more than I do... Doing a water change first thing in the morning and see what happen from there. Thanks for all the help guys....