My BOW has a pH of 6.5 even after liming, due largely to acidic watershed. Most watershed is planted pine.

Question: Would watershed become less acidic if pines are thinned? What about if pines are clear cut and then land replanted?

Any thoughts? Pines at perimeter of pond would be left alone in either scenario...

Did you lime the watershed as well or just the pond?

Just the pond, unfortunately. About half watershed is not on my property, though I could talk with lady who owns it.

Frank, have you tried adding some of the agg lime around the waters edge and let the windy waves mix it in. I have done that along with adding it to the wash where the majority of my water comes into the pond during rains. For me, after I reached my desired pH I still continue to do the things mentioned and freshen up those spots on occasion as needed.

Add more ag lime to the water. Its not the pines. Pines grow in acidic soil. The pines are a symptom of the soil. You can't change the soil in the whole watershed easily so concentrate on the water. By adding ag lime you can buffer the water (higher alkalinity buffers the water) so that ph swings are small.

After initial application, if you have a wash or point of entry of water that tends to erode, I like to put lime 6" to a foot deep in that area. Then as the water flows over the area during a large rain event, it erodes lime into the pond rather than soil.

When it gets washed out to soil again, add some more lime. This is likely not adequate for initial treatment, but a way to treat incoming water in small amounts over time.

If you have a tractor and front end loader, just keep a pile of lime around in an out of way place and add as needed to the area. One caveat. The lime will tend to harden up in the pile like poor concrete. Can usually put the loader bucket edge to scrape up some loose material but it will take a little work. We hate it when we have to let lime piles sit and not get them spread on the fields right away. But small amounts to break back up are manageable.

When my piles of agg lime sets there it get a little weathered and will break down into smaller particles and or powder. And when I add that to the areas suggested, I find some of it dissolves into the water pretty easy and will raise the pH pretty fast and the remaining agg lime will treat the new rain water in the area where it enters into the pond.