I feel a restart is the only option because ive been trying everyones advice and it keeps coming back. new bulbs, less lighting time( down to only a couple hours a day), feeding less(down to every 3 or 4 days), r/o water(ive tried 2 different local aquaium stores) frequent changes. Ive tried chemi-clean, which knock it down pretty well, but it came back and the same product didnt do as good the next time. went as far as moving the fish and some of the live rock to a spare 30 gal tank, hosing down the rest of the live rock, cleaning the tank and pumps( tho I didnt use chlorine that time) refilling, live rock back in, cycle the tank, fish back in, hose the rest of the live rock and real good rinse of the substrate. couple months later, Its Back. So this time, ive moved the fish and some live rock again. I have a bunch of old coral(not live) from before I went with live rock, soaked them in a chlorine solution(10 %), am going to buy some new substrate, clean all pumps and hoses--- everything again(with chlorine) and start again. Maybe the live rock has been holding it somehow? I dont know. I just dont have much more hair to pull out. this site has been a big help for me. thanks