my pond is around 2,500 gallons and is almost six feet deep. as far as oxygenating the water, my pump moves 1,200 gallons per hour through a 4 inch line. my neighbor has a much smaller pond with no waterfall and has had trout living in it for years. a few of them are almost a foot long. anyway, the trout are only an idea, something for my daughter to fish for when she gets done with school.