Finally, my pond is in Mississippi but I live in the 'burbs of New Orleans. Sounds like your acidic red clay soil is like my pond. You'll need to get some ag lime spread in the pond before you let it fill in. Get some samples of dirt and send to the La. extension service; you can get the pre-addressed boxes with instructions from any extension site. My expectation is that they'll suggest 3 tons/acre of ag lime if your soil is as acidic as mine. Before the pond fills, this will be the best/easiest time to get it spread out along the pond bottom assuming your pond bottom is firm enough to allow a spreader truck to get in there. You will need to take water samples every year to check the alkalinity of the water and adjust (with lime, of course) if too low (<20). It will be difficult and/or expensive to distribute with the pond full, however. For this reason, I'd suggest adding extra on the initial spread as you really can't "over" lime IMO.
1 ac pond LMB, BG, RES, CC
