@Charles08 Hey there!
It seems we’ve been asking a lot of questions about your pond, but we’re not getting much info back from you.
The way this works, is you give us as much info as possible about your pond (IOW, the questions we’ve been asking you).
We can take that information and try to help you figure out what is causing your problem and try to help you come up with solutions.
All we know is that you have an algae problem, that your pond is (apparently) at the end of a downhill run-off, and that you’ve been using chemicals to stop the problem (without success).
I don’t mean to sound rude, but we can’t help you without your help.