So is it just trial and error when adding gypsum to increase hardness or is there a formulated amount to add per acre? I can get gypsum by the bag, but it's kind of pricey. I can add more AgLime, and probably should, but so far it's not improved my hardness at all.

While I'm thinking about it....should hardness be relatively equal to Alk?

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!