Wow, that is some low pH!!! You must be in heavy pine. I'd suggest getting as much Ag Lime as possible (6-8 ton per acre) in the surrounding woods that run off into the pond, and another 10+ ton of Ag Lime spread into the pond. It will still take a few weeks to a few months to raise the pH a couple points.

The acid is washing into the pond, so neutralizing as much of the source as possible will give the best boost.

Another option that is also faster acting, would be Calcis, (Liquid Lime). It is not a true Ag lime, but contains a concentrated calcium that will help buffer the acidity. It is a bit pricey, but with difficult access for spreading Ag Lime, it may be an excellent substitute.

Last edited by Rainman; 06/08/16 06:29 PM.