I am trying to combat the hair grass with tilapia. I have had them in aquariums for years. This year I released about 15 large tilapia into the pond 4 weeks ago. They have already noticeably reduced the filament algae and hair grass. The tilapia also started showing up when I feed the catfish. The tilapia will die over the winter as they are tropical. I am going to buy one of those electric fish stunning systems to see if I can get them out and eat, or put in the tanks in my shop to over winter. I calculate that those tilapia could reproduce about 36,000 fry by winter. I wonder if I could stun and float of bowfin! Hummmm...
My pond may be kinda big, being 1/3 acre and 28' deep, but to me, it is my monster fish tank and I am now actively starting to stock it with cool fish. Black mollys and sailfin mollys are next on my list as sailfin mollys are native locally. I can catch them with a dipnet. They have not shown up over the 11 year life of my pond as they are live bearing, not egg layers.