add a skimmer or replave your carbon often.
what size tank is this on?
i would also like to know if you are using RO and your bioload.
I have a 10 gallon and that's why i don' thave a skimmer. I am using RO water.
In my tank i have:
1 purple firefish
2 nessarius snails
2 cerith snails
4 turbo snails
8 bluelegged crabs
1 scarlet crab
hammerhead coral
bunch of zoos
mushroom rock
ricordia
that's about it. i was going to get a percula clown later on.