do a search, it's been covered a few times lately...
make sure you're vaccuming the cc with each water change, decrease feeding, increase water changes, increase lr and other filterations, add some inverts to clean up-that'll help with nitrates
I have flordia crushed coral.. Does that mean that my tank is going to screw up!!??!
what's flordia cc? any cc is bad, sand is better
What did was cleaned an area of cc very well, then removed 2-3 nets of cc. I did this with each water change and started doing weekly water change. You MUST clean the cc or you'll increase nitrates by stiring stuff up. Also, be careful when moving lr around, that'll stir stuff up also. So move the lr, wait for stuff to settle, then clean the cc...you can clean a larger area than you remove, just make sure you clean the area you remove.
or take the tank down, empty out cc, replace with sand, set tank back up. this will work if you have a qt for your fish/inverts...in case you get ammonia. Either way, clean the heck out of the cc before removing it (unless all the water is out of the tank)