It's just so darn...icky! We enjoy swimming in the pond (well...floating on rafts and drinking beer is closer to it) and this stuff just totally discourages that notion. The fact that the pond gets no runoff is good in the respect that no fertilizers or other gunk gets in the pond, but it also keeps this goo from floating away. I guess I'll just keep vacuuming it off as the wind piles it up in one of the corners. I'll also start running my make-shift fountain full blast.