Trying to decide whether to add fertilizer this late in the year. I have maintained a nice bloom pretty much all summer by adding fertilizer whenever the secchi depth would exceed 24", but I stopped about a month or so ago because the FA was becoming an issue. At that time, I added 5 lbs. of copper sulfate crystals (1 acre) and I'd say 95% of the FA is gone now. Unfortunately, so is my bloom. My current secchi depth is 48" and, while I enjoy seeing all of the fish etc., I know that I need more planktonic algae in there to support the food chain, give cover, etc. So my question is whether I should fertilize now to encourage a bloom this late in the year, or just leave things as they are to be safe? I was thinking maybe adding half rate, and then see what that does? (3lbs or so of 10-52-4) What do y'all think?

What is water temp.? If still above 70 you can add a little fertilizer. It is late but if warm will work. I would add no more than about 1/4 the normal amount. The FA was not caused by fertilizing this year as it started growing on your pond bottom last winter. It comes to the surface at the end of its life cycle floating on the gas it produced during growth.