I Was curious what fish if any people have in there frag tanks. I have a 30 breeder with a 55 sump. Never had fish in it. Just a few snails and hermit crabs.on Friday. a friend broke down his tank that was neglected and gave it all to me. My tank was just about empty from the swap so I. Have room. Problem is his rock and coral was covered with flatworms and bubble alge. I put 3 emeraled crabs in it and was thinking of adding a sixline anything else I should add. He had a beautiful tank at one time. I have 2 other tanks in my house so when I bring this one back to life I can have my frag tank back.