hermit crabs do survive in brackish water which is 35-40ppm. Normally it can be found in the stream which near to the sea side.

I house my cray in the 6ft tank with rocks and fine sand. Cray fish do like strong water flow. Especially the Australia Blue do survive in temp of 10-16C and fast flow river. And they breed only in low temp. But those from farm is not hard to breed. All you need is a chiller to chill the temp around 20C.

crazymouse....where you house the cray is not recommended to keep any aquatic plants. I can said all cray do dig. No matter your plants r real or fake. And it will keep you busy to plant it back.

Do some research online. You will see those home breeder keeping cray in plastic container. They keeping 1 container each. All seperated.

Check out http://www.bluecrayfish.com and http://iz.carnegiemnh.org/crayfish/phpbb2/index.php