So yesterday I did some massive cleaning of the system. This morning I woke up to one of my purple tangs dead . Attached are some photographs. Recent events , added f conchs to help with sand bed. Cleaned up the system. Note. Was healthy and no signs of any issues. Fat as can be. I have been having some issues with phosphate abs dosed 3 ml of seaklear into the skimmer. Skimmer is in sump which is basement. I am hard pressed to think it was the lanthanum chloride. All other fish doing well. Eating as usual. I do think I have some worm issues as some of my wrasses have large guts bombs. See the pics attached. Water parameters normal. No amonia ect