Follow these few preventive steps before blue green algae, string algae and cyanobacteria become severe and persistent problems in your pond, requiring a more aggressive treatment. We caution clients against using only algaecides in ponds, as aeration, bioaugmentation and controlling pollutants entering the pond are the preferred long term solution and should be the first line of defense. Over dosage of an algaecide can harm plants, fish and critters in a pond, so it is with caution that we use algaecides, and certainly with careful dosing in consultation with our staff.