Here's a scenario for the forum.
I've got a 1/2 acre pond that I've been fertilizing to produce a bloom. This pond has a history of filamentous algae problems. Now I have a bloom but still have filamentous algae around the banks in shallow water.
Tried a really light dose of cutrine targeted to filamentous algae because I want to keep the bloom, but lost a lot of the bloom and filamentous algae still a problem.
The dilemma:
Use cutrine to control filamentous algae and lose plankton bloom, or use copper sulfate on filamentous algae and keep the bloom. Since application rates for control of planktonic algae with cutrine are about 1/2 that for control of filamentous algae, how do we effectively use cutrine for selective control of filamentous but not planktonic algae.
I feel that if I'd diluted copper sulfate and targeted filamentous algae in this pond I'd have kept my planktonic algae bloom...or that it would have returned within a few days.
Details: treatment rate with cutrine was 1/4 gallon in 2 acre-feet of water. I would have used 5 lbs of copper sulfate had I known the consequences.
This treatment with cutrine was done on an experimental basis, because of the posts on this thread. I think next time I will try diluted copper sulfate and see how the respective algae reacts. It is cheaper, works quicker without residual concentrations in the water comumn, and seems to give better results in this type of situation. I'm not concerned so much with residual copper in pond sediments. I'm interested in a planktonic algae bloom with minimal filamentous algae, so we can harvest the pond without problems.
