I live in New England and I've got a 55' by 25' new garden pond which has a depth of 3'. The pond has a big water fountain which works 12 hours a day and this Spring and Summer we had loads of frogs and tadpoles. We also have loads of insects (boatmen, water skimmers, beetles, dragonflies etc). I tried to introduce some minnows but they are all dying one after another. I just had the water tested which is perfect with no amonia or nitrate. I am not sure why the minnows are not surviving except for the fact that maybe the water is a tad too warm for them. Anyway, I would like to add some native fishes in the pond but not sure which ones will live in harmony with frogs and tadpoles. I read that mosquito fishes are toxic to frogs. Which fishes can I add?