Kolar Labs Bulk GFO Phosphate Reducer 5 Gallon Bucket (20 lbs) $403.19 This GFO is the Original GFO Bayoxide E33. High phosphate levels are a recipe for disaster in saltwater aquariums. It is a nutrient for nuisance algae and also hampers the formation of calcium skeleton in corals. There are several different methods for... Add to Cart