No Crustation is safe in a tank with any eel !! If I where to put one in a reef tank, it would be a Blue Ribbon Eel b/c they don't get very big & that's less chance of your corals being knocked over & around all the time. Besides, if you have a "very small" tank than an eel is the last thing that you should be putting in your tank. they can be a messy animal so your water quality would always be horrible plus Eels' just don't belong in smal tanks to begin with. I think the minimum tank size is supposed to be a 55 gallon? Don't worry...some of the experts will soon be here to tell you why it's a bad idea.