water changes through off bio. filter?
my tank was cycled and going well, then i had ammonia and nitrate problems, no nitrite. ive been doing water changes daily and my nitrate has gone down but not my ammonia. im afraid if i keep doing the water changes im going to upset my biological filter. ive run out of bottled cycle, i do plan on getting more but should i stop doing the water changes? every two weeks the water evaporates about 15% and i add new water anyway. what should i do to bring the ammonia down? ive added ammolock and nothing. ive cyphined the gravel and done about 10 water changes in the past week, still no change in ammonia. i lost 6 fish to fungus\ ammonia poisioning, i added aquarium salt and rid ich. the rid ich cleared up all the fungus growing on the fish and ive stopped using it after two days. i reduced feeding to once a day and my angels have been eating it in 1 minute. the one angel has white thin feces and seems to be getting less food then the others. what should i do? thanks in advance.