Lots of interest in this subject. Thought I'd add my tank and see if we can share ideas. Some of you guys are old pro's at this yet I am just starting. Here is what I have....... First I promised the wife automatic waterers for her horses in exchange for one of her half poly drums (hehe).... I then used refrigeration grade sheet insulation (left over from a job) and made a giant "hugger" to insulate it. I used a blue drum because I read that the blue color calms the minnows. I picked up a 110v air pump from academy, added well water, better bait and dropped in my left over minnows.