Cecil,
You have me wondering by using well water would it be possible to keep my pond cool enough to raise some cold water species?
50 gpms into a 1/2 acre pond will not keep it cool enough for trout but could keep at max temp of 75 F. When I ran my 45 gpms from the trout pond (lower 60's exiting the trout pond) into my .62 acre pond my pond never got above 80 in the summer. When we swam in it we wished it would have! I now bypass the .62 acre pond as I am going to dye the pond to keep Chara down and want to use more and more of the trout pond overflow for irrigation of an expanding raised garden.
However you could dig a 1/10th acre steep sided pond upstream of your 1/2 acre pond and that would work. Then overflow that into the 1/2 acre pond. The smaller pond would also allow the iron to settle somewhat and release gases. Not sure if you would need to go to the trouble of dropping your well flow into plastic media, or something similar, or not, for the trout pond. My method may be overkill.
