Well, it's like this...
Our water is very clear, but algal growth, while not explosive, has been steady, esp. since a 3-day power outage where the UPS also failed and killed _either immediately or eventually) about 70% of our inhabitants. Dead inhabitants were removed inasmuch as possible, but it is going to be some time until we are going to be able to get the tank completely cleaned up. We were also originally using treated tap water, but are now the happy owners of a 100gpd 6-stage RO/DI (w/ tank) for about a month now. Things are slowly clearing up, but the RO/DI has rocketed up our pH. Adding sand is not really feasible, as our sand-bed is already a good 6" deep (incl. the 1.25" plenum) and that's in a 50gal. Nitrates and Nitrites are not high, they're not off the scale... they're not ON the scale. Phosphates (from all the earlier tap-water) and decaying matter from die-off is the real problem, I think, and I was just hoping for a way to mediate whats there until the whole mess stabilizes as I gradually introduce new livestock. and creep pH down to a more reasonable level. pH has also been a nightmare, as my water is naturally high right out of the RO/DI, and with the kalkwasser drip we had, the tanks buffering capacity is... vast.
Anyway...</em> There is some algal growth on my corals, and if this product is actually effective and safe for my tank (as algacides are not) then I'd be willingly to give it a go until things stabilize.