On my hot tub I have an ozanator, That is supposed to take care of the algae. I have a gallon of silver cooking. I'm going to try that. H202 is corrosive and might ruin the pump. Might add Iodine every week for safety, and as a shock. I stopped at the feed store yesterday, and they have fairly cheap iodine. Would be fine for a tub. At least I won't be soaking in hazadrous materials.