Thanks for the plant info. The old timer that got me into ponds was big into the natural bog dealio. I've read it in a book or 2 also so I figured there might be something to it. If nothing else it helps aerate the pond. Filter might be the wrong word to use but you have to admit...those cattails had to eat something. Fwiw I have no soil, just a membrane lined pond. Maybe 20 koi and a few small catfish. all the koi under 2' long. Again thanks for the info, if any one thinks of more good candidates let me know.
