awhile back i had 2 fish die on me within a week like 5 months ago, both had died early in the day and by the time i got home they were pretty much consumed by my cuc leaving little chunks all over, after that i had some high nitrates and phosphates, with combination of this and using an old bulb on my MH unit GHA had grown and spread all over. i also changed out my fuge substrate from crush coral to aragonite because i suspected that to be a source. i have battled down all possible nitrate sources, and now my nitrates have been untracable for 2 months, i pull a handful of chaeto out a week, 10% wc each week on the dot with RODI, have been very carefull with feeding, and have a brand new MH bulb, yet this GHA presists... i am 100% sure there is no more cause in my tank for high nitrates or phosphates. i just cant get this stuff to starve out. i siphon what i can each week when i do a water change, but it doesnt seem to help. i noticed it only really grows on certain rocks if that helps.. any suggestions?