I put 25 rainbows in my 1/3 ac pond and 3 floated up 2 days later so I thought they were probably all dead. Just a few days ago I started feeding them regularly and to my surprise I can see 7-8 at a time taking feed. This pond is 11feet deep and doesn't have aeration yet as I am still in the construction phase. It is ground fed sandy bottom so it is fairly cool so far this year.
Try feeding just before dark and spend half hour watching for action.
