Another "thinking out of the box" idea (some may think I am mad as a box of frogs).
I have built and used with success algae scrubbers for my fish tanks but I have not seen many applications of the concept to ponds, this is one of the few
https://youtu.be/nsyX860SimI
I am seriously considering giving it a go, not only would it export waste substances from the pond but hopefully to some extent "starve" hair algae from growing elsewhere.
Any thoughts?