I have kept fish with turtles and sometimes it works out, but there are always a few fish losses. I have kept painted turtles with tetras and only had a few fish eaten. I have kept softshells with fish... that was a lost cuase for the fish I tried in that tank(convicts, firemouths, buenos aires tetras, pristella tetra, and a few other random oddballs). None of those fish lasted long at all, but there is one feeder goldfish that is a trooper who lives happily with them now. I think that is you put in baby turtles at the same time you place fish in the tank (and make sure the fish are the same size or bigger than the turtle) you'll be alright for a while.
And for feeding, it depends on how you feed the fish/turtles. Most of the foods my turtles eat these days are floating pellets, so if you fed your redhooks something that actually sinks in the water and feed your turtles floating pellets you'd be alright. Or feed the fish on one side of the tank and the turtles on the other (make separate feeding stations for them). And don't under estimate the speed of turtles. You'll see how fast they can be in a big tank. My big female softshell floats around like a lame blimp all day, but if any food hits the water on the other side of her pond she shoots over (goes 8' in about .25 second) there splashing water everywere and nabbs what ever it was. Sliders and other hard shelled turtles (excluding FRT, I've seen those suckers move out!) aren't quite as fast, but they can scoot. So I'm not sure about how fast redhooks are but the faster the better. I have actually been thinking about putting some Bala sharks in my turtle pond. I know they are pretty quick.
As for turtles in a planted tank... it can be done but only for a little while with baby turtles. Baby softshells are nice becuase they don't eat to much plant matter, but they like to dig them up. They bury themselfs in the substrate. If you did want to try softshells, everywere you have plants in the ground, cover around the bottom of the plants with big river rocks. That way they won't dig right under your plants every day. Once they get bigger they will dig under everything. I have a few rocks in my pond that are about 10-15lbs and they are in a different spot on a daily basis.
Well thats all I can think of right now. If you have any Q's fell free to PM me or post here again.
?). I am more concerned about the fish, which is why I chose this forum and not the "other pets" section. Do even softshells need a place to rest outside the water? Anyone successful with live plants in 
