Easy, I find them no harder to take care of than lets say a motoro. Any ray that is small, pup size, is of course going to be more sensitive to any change in water quality and will be affected far worse by any sickness or parasite cause they are young.
I have kept three motoros and four retics, and have lost one ray, and that was an 11'' motoro, the 5'' retic in the same tank was fine.
So as long as you keep up good water quality you should be fine.