Would there be any sea urchins suitable for the 34gal cadlight tank? i i do plan on keeping corals and such but im woundering if i should/should not concidering getting an urchin (if i do i would be suplying it with supliment feeding ect, im just worried if the tank may be to small or wether it would be to dangerous for it to be in there or....)... the two urchins that cought my eye is the tuxedo urchin and the long black spined urchin.... any ideaS? thanks!