light could be trigger more algae growth, I'd recommend some water changes and consider a UV filter, which should break down the algae cells in the water column. also, what kind of skimmer and other filters do you have on the tank? if it's that seaclone and concoction of cannisters in your signature, I'd highly recommend removing them all and getting a better powered skimmer. you could be fueling algae in the canisters, and the seaclone isnt nearly adequate for the 125.