"NJ" wrote in message ...
"tom" wrote in message
...
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?)

Tom,
Where are you? Here in zone 5b, we have had chillier than normal
temperatures and a ton of rain and clouds. I had to throw out all my water
lettuce ($$ down the drain!) because it got yellow, then brown, then mushy.
All other elements in the pond are great: fish health, water quality, etc.

NJ
The thing to try is Muriate of Potash availsable at most garden
centers. Dissolve 3 tablespoons in a liter of water. Add 1/8 cup/100
gallons of pond water twice a week. When the plants green up you can
cut back to once a week. My plants died the first two years until I
found out about potash. Good luck.