Ive been told over the years that in order to keep them alive very long you must have a tank that that has been established at least a minimum of one year, but longer is prefered, i tried them the first time i started a saltwater tank about 10 yrs ago, they lasted about 3 weeks then started goin down hill , thats when everyone told me they was starving to death because my tank was to clean, all though all my other fish and corals did fine, wish i knew for sure id love to try um again!