I’m shutting this idea down for now, the field south of us is planted in cotton, which is a very chemical spray heavy crop. I’m thinking the drift cause the die off I had, so now I’m working on a new pond idea on the covered porch. Trying to keep from going overboard. But if I keep it simple, a wooden frame 30”x82”x73”, lined with either a liner or marine grade epoxy, with bog boxes along the railings, and maybe a shelf with supports. A simple pump in a filter box, pump up to the bog boxes, which would fall the water into the bog shelf or back into the pond. Filtration, circulation, and airiation all in one. That part of the porch has a water spigot and power outlet right there. My big concerns are are leaks and drift from the cotton field. It’d be easier to cover that with a tarp to keep drift out.