sorry, tank is 2 months old, i have two clarkiis,urchin, tile star, cleaner shrimp, fire shrimp, bi color dottyback, sixline,cuc,torch coral, bta, sun anemone, zoo frag, 2 brain coral, sun coral, 2 coco worms, and the ladt thing i added was a piece of cured live rock...could that be the culprit?