First off I screwed up and am aware of that. 2 small oscars 75gal tank. Fluval fx4 for about a week than added fx6 both with additional sponge and media Constant ammonia issues low nitrites and low nitrates ph about 7. reduced feeding the past couple days small water changes pretty much everyday 10-15gallons. 30ish gallons every 3-4days. Today I noticed cloudy water ammonia maxed out on api test kit. Changed about 65 gallons tonight waited couple hrs checked again still about 4ppm. Been using ammo lock. Anything else I can or should be doing. Fish have been doing great a grown like crazy in the about 3-4 weeks I’ve had them