fish that work with crayfish, at least 4 me.
I have roughly 9 blue crayfish in my 72 gallon bow front setup. The smallest one is roughly 1 1/2 inches, the biggest is around 3 1/2-4". They and my other fish seem to get along just fine. The clown loaches are the only ones who seem to get a little torn up, but thats because they tend to just lounge around. I feed them sinking shrimp pellets. They don't seem to be scared of coming out to play. I have lots and lots of hiding places setup in the tank, but they also like to build there own.
All the fish except for the loaches and scat are 3+ inches long with the pleco being the biggest at over 6". I've got 3 silver dollars, 2 mono's, 1 pleco, 1 pictus cat, 2 clown loaches, 2 african chiclids, 1 green scat, and 9 blue crayfish.
My water temp is around 80F and is brackish. No issues with my heater in there. I've got dual aquaclear 500's and a ebo jager 250watt heater.