6mos old PC fixture on a 20 gal. may be too much light, I put a magazine over chili so he won't get so much. I let the phosphate get too high I guess. I'm reading some. I have a few mushrooms and the chili coral, bt anemone, maroon clown and red hawkfish and a brittle star who got his arm ripped off last nite in my powerhead, thank God I heard it and unplugged it, I think he is going to die, hasn't acted good since. A piece of silverside slipped up near the powerhead and ole log arms had to go exploring. Poor guy. I toothbrushed Chili and it is coming around. Did a round of Chemiclean 48 hours and 25% wc tonite, maybe that will help. He already looks better tonite, polyps showing.
The Boyd's CC is a good product for cyano!! Awesome. Only takes 48 hrs!