My floating plants (lettuce and snowball) seem to be dying on me. I have a
small pond, around 800 gallon with 9 small fish. The greens are turning
brownish around the edges and generally looking unhealthy.

The water quality seems good, and the fish are doing well. I have a
waterfall, bio filter, and a floating wood chip thing (for keeping down
slime levels?)

Thanks for any help,

Tom