I set up a pond every year. I live in Michigan and you only have a short peroid of time to keep fish in it. I get it up and running in late April, and by early June I start putting Fry in it. At that time the temp is up to 75 to 78 degrees. Like I said I use it as a grow out tank and it works great. I do have to worry about birds sometime but I dont have to worry about racoons because the fish are small. And with Michigan weather I have till about the middle of October befoer I have to pull them out. In that 5-1/2 months the fry normally will triple their size. By mid October I pull the fry and shut the pond down till the following year.