Interestingly I put in a baby gate in the shape of a box (white), the thing is as clean as the day I put it in last fall. No algae whatsoever. Chara is here and there, and I planted a bunch of, um, the grass-like plants I collected up in the ADK. I think the CLPW is finding and capturing the free nutrients in the water before other plants can get to it. New pond, low nutrients.