Pull out the floss and run just carbon for a while in your cannister, after this clears up, stop using the cannister at all, so long as you have good LR.
Test your water. We need to know salinity, pH, alkalinity and calcium levels by testing using good quality test kits (like
Salifert kits). Make a list of ANY additives you're using in the system now, including any food additives. If you're feeding the tank now, stop.
Are you the only person that puts dditives (and food) in the system? Give us an idea of how much of everything you're putting onto the tank, including your top offs, brand of salt, and what type of top off water you're using every day. Give us a list of what you do to make your water changes, and also list anything you're putting into your top off water (remember, it is FW for topoffs, better to use only RO/DI freshwater, no additives)
HTH