I have for a while had a cold water marine fish tank local to Cape Town and surrounding areas. Does anyone else have similar that can make suggestions. I only have fish/shrimps/hermit crabs and anenomes in it. Size is 1200x450x450 with sump. I don't really have problems but maybe others can give advice. I have basic lighting (1 blue and 1 white) and obviously use a skimmer. Is it possible to have anything else in the tank, and the same principals that get applied to tropical be applied to the cold water system.