I just started using it to clean up a turf algae that none of my fish or clean up crew would eat. It's been a week and 4 doses and it's decimated it. There are no apparent side effects so far, and I plan on only using it until I get the turf algae under control. It is a bandaid if you don't have good nutrient removal, but I do, but the turf algae was out competing the chaeto, way oversized skimmer, uv, carbon and gfo.