CPO adults are as hardy as.... well, any typical crays. they can take pretty much any water type, but prefer harder water. i keep mine in straight tap (ph 7.8-8.0, TDS ~320ppm). they are not long lived though, around 1.5 years. if you do buy them, make sure you get juvi's or like CRS adults,they wont last too long. the young are what i would call "dumb" though. instead of hiding all the time, they posture and flare at anything and hence get eaten by fish more often than not. i only treat CPO's more carefully because of their cost compared to say a regular c. shulfeldtii. hopefully they become more common in the hobby, but they dont breed as readilly so that is the problem. i have had several females killed by overzealous males during mating or right after when berried.