i dont understand exactly what your saying, but if you thought i was saying i didnt have a powerhead, i didnt mean that...i HAVE a powerhead which pushes 660gph around in the main tank. what i DID mean was i dont think i have the "DI" part on my water filtration system (its just a ro unit, when i bought it i didnt know the difference.... ) but, i have a clown, tang, and blenny. no damsels. they all share their food and get along very well. what should i do? i have a ro unit, but i think i need a ro/di unit, i dont want my money to go to waste... is their some way i can just add on the di? or swap out my ro for a ro/di? please give me some suggestions! could not having the "DI" have caused all of these problems? i'll be back on here tomorrow evening/night with my water parameters. i'm doing a water change tomorrow morning. i dosed my tank with chemiclean 2 days ago, it helped slightly, still a long ways to go. but i'm going to bed now, hope to see some replies when i get back on ...thanks, you dont know how much all of your suggestions have helped.