I wonder if we are trying to keep out pond too clean. DH cleans the bio well at least two or three times a summer. It gets so gunked up with algae. Maybe the answer would be more bacteria. I use Aqua Meds brand and Microb-Lift. Also we scrub the gunk off the bottom and sides as best we can as it looks terrible. Not long but just yukky. But then I am not trying to cure green water. Mine is crystal clear, it is just that the sides and little creek from the biowell to the falls gets pretty gunked up if we don't keep on it. The skimmer has to be cleaned at least twice a day (probably could use more) as it gets clogged with the dead algae being sucked in by the pump.
