Using hydrogen peroxide to control turf algae has been very helpful here at Trop. I spray it on, undiluted, put the rocks in a covered bin for 1/2 to 1 hour, rinse, and return to tank. There is little harm to the coralline algae, using this method. The problem is that one of my smaller vats, 1150 gallons, is beyond saving in that manner. Is there a ratio that can used on the whole vat that will kill the turf algae without killing the coralline algae?