we are also in n. wis., had rainbows for two yrs, they were 5-7"when put in the pond. One yr later avg 12-13", they had been fed pellets and lots of minnows and tadpoles. Then that fall and next yr, we could not catch or find a one. No reason just gone. Even the hbg are gone. Put in the largest you can justify and keep whatever u catch is our opinion. Or something else will. We ran our aerator 24/7 in the winter and at nites in the summer/ Good luck
Two legged predator perhaps? Or an Otter?
