I don't know what to do I have a little problem with the ammonia about 1.ppm and I can not get rid of it I have 2 hang on the back emperor by Marineland 400 and a canister Fluval fx6 I have been doing weekly water changes as always and have gotten a little Spike I do not change all the media at the same time as I do the water changes I need help and btw thisis a 180 gallon