Even with the addition of an automated feeder to the pond, would tilapia stocked at a lower density (5-10 lbs per acre) be an efficient way to maximize available forage for green sunfish? Also, since any fish over three inches long is out of the mouth gape range of the all but the largest green sunfish, could tilapia cause biomass issues in the pond? One of my concerns if that even though tilapia are tolerant of lower DO levels, my other fish could be put in jeopardy due to more pounds of fish in the water and, consequently, more oxygen being used up.
Conner, a low density stocking will not pose any new DO worries. As Dave mentioned, in most pond settings with detritus/muck on the bottom, tilapia will increase DO in otherwise anoxic parts of the pond. Tilapia will grow about an inch a week to 6" then add more girth than length, so I'm sure many GSF will get fat and happy too. My only concern is how many Tilapia would survive predation and possibly cause an aesthetic issue when dying once your pond cools. There is no danger of an excess load of nutrient, even if terrestrial critters don't perform a quick cleanup, because any unused, unbound nutrient not used in GSF growth, is just recycled from what was already present in your water.
