i've been raising marmokreb crayfish for a couple years.. mostly as a supplemental feed for my yellow perch, bluegill and tilapia..
marm's aren't as territorial as redclaws, but redclaws definitely grow big! i'd like to try them but my winters get too cold, and i don't want to spend that much heating my basement..
anyways, i keep my breeder crayfish in 55 gallon glass tanks, i filter these with sponge filters.. when i get a hatch, i feed the babies until they get to 1/2" or so then start using as feed..
i've let at least 40 larger marms go in the pool to grow out, i figure i'll have a meal of them in a year to a year and a half for me and the wife.. i love to eat em, but for me, they're more practical as a supplemental feed for my fish