Yeah it would probably have to be a partial recirc to keep water temps down for trout with a continuous small level flow through the system from the well.
I've decided to make some changes to my well pit area and enclose it to make it biosecure. Right now it has chara, snails, and i even saw a frog in there. I already have about 150 feet of buried 4 inch PVC headed to the trout pond complete with a gate valve to cut off flow to the trout pond and send it around the pond.I'll just extend it to the pole building to decrease digging.
I like this little DIY sand filter and think it would work well for iron removal. The inventor uses it to remove fines in his koi pond to produce crystal clear water. I know it will work to remove precipitated iron as I use filter material for a much smaller amount to produce gin clear water and this seams more robust.
This is the same guy that I duplicated five moving bed filters in a 55 gallon drum from. They will take up to 5 cubic feed of media which is a lot of surface area at 189 ft2 per cubic foot.
http://www.koiphen.com/forums/showthread.php?69030-Birdman-s-Sand-Gravel-Filter 
