Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants help with cutrine plus application

OK, I'll join the confused list too. My pond is about 1/5 acre. I read that for planktonic algae, .6 gallon per acre. My calculations figured out at about 15 ounces of Cutrine plus. I mixed that with about 135 ounces of water. Due to amount of algae, I split that in half to reduce the shock to the pond. I sprayed it on Saturday morning and by the afternoon, I could see a color change and a little clearing on that half of the pond. By today, the algae is completely back again. My question is, 1/5 acre is a surface measurement. Do I need to multiply that by average depth and use Cutrine according to that measurement? If that is the case, 1/5 times avg, 6 feet deep, 1.16 acres, which would be .6 gallon.