I am baffled, but after having NO algae with my "in pond veggie filter" this spring I
suddenly got algae. The temp had dropped again (outside and in the pond). I turned
on the UV and in 3 days it was clear. But I am surprised that the algae reappeared.
maybe because the pond was getting more sun. sigh. so my hope for not having to use
the UV are once again dampened. Ingrid