I just drop them right in. They're quite hardy.
They will be fine with any fish that can't eat them, and isn't known to pick on other inhabitants, and any fish that aren't slow moving, or sleep or rest on the bottom in one spot for extended periods of times. Many won't bother any live fish at all, but some will.
Provide them with a cave (a flower pot or pvc is fine), local driftwood, and plenty of substrate for digging.
You don't have to use river water for them. You can use your own dechlorinated tap water. In fact, some species can survive in acidic conditions, extreme high pH, tolerate high levels of various pollutants, and even live in very low salinity conditions. The red swamp crayfish, the kind that is most used for human consumption, mostly collected in louisana, is one that is extremely resistant to all of the above, and can even be found in full brackish conditions sometimes.
Of course I don't recommend exposes your captive specimen to such. Keep them in regular room temperature fresh water, and keep the tank clean and cycled just like you would a fish.
Always leave the molted shell in, as they will eat it to regain nutrients lost during molting.
I dropped a few in to my 29g cold water tank with my sculpin..she ate a few and the smaller ones are thriving..im in WA so my cold water tank stays around the 60-65o they have logs and rocks to hide under,
java moss, anubia, penny wort, and water sprite for plants.
depends on your tank. your temps and where you get them from (temp of water they come out of)
Be careful depending on species. Many will eat plants, especially the Orconectes sp..
Mine decimate most of the plants you mentioned. Plant matter is part of the natural diet for most of them. Also wood, leaf litter, and algae.
Anubias may work, but I haven't tried it yet.
