One of the newer products on the market, “Green Clean” kills algae via oxidation and the results are very rapid. There is no residue and it is not copper based. Though it is advertised as a “broad spectrum” algaecide users have reported that it is best for string algae and not ideal for green water (free floating) algae.
Note: It is best to turn waterfall pumps off, treat waterfall, wait 20 min. then turn pumps back on.
Note: may raise pH up by a factor of 1 -may need to test water in days after application.
Check out the first 4 minutes of this demonstration…