My pond has a pH that ranges from 7.6 in the morning to 8.0 in late afternoon. Alkalinity is on the low end , about 25 ppm. Hardness is also on the low end, about 60 ppm. Visibility had been real low (2-3") since Hurricane Ike but 2.5 tons of gypsum and a break from heavy rains has cleared visibility to 18-22" depending on the bloom density in the past 5-6 weeks. I have a pretty good bloom going which I have helped along with inorganic liquid fertilizer. No big problems with aquatic vegetation. I have some FA but fertilization seems to be reducing the FA and I am also mechanically removing floating FA when I can.

I feel like I need to have higher alkininity to guard against pH swings (30 ppm +) as well as give myself a fighting chance of keeping the water from going all chocolate milk on me this winter. I'm thinking a slow addition of Ag Lime between now and winter will get me where I need to be but since my PH is already on the high end I want to be careful with it.

1.8 acre pond, one 15+ ft deep spot, average depth of 4+ feet. Pond was stocked with 200 8-11" northern LMB, 200 7-12" CC, and 1000 3-5" CNBG last July & 25 lbs of Mozambique tilapia in early May. There were a few resident CC and GSF existing when it was stocked. Fish eat an average 4+ lbs of hi protein feed a day, none goes uneaten. LMB and CC are growing at a high rate. A good amount of visible YOY, mostly GSF and BG I think.

Is a slow addition of Ag Lime over the next 6 mos a good plan?

I'm also giving strong consideration to adding aeration later this summer.