By the way its a 10gal no filter as of yet have a canaster the I may use just for bio filtration its on the tank but im not sure if im going to use it. I also have no skimmer I do a 10% water change weekly and add Kent Essential Elements every other water change. It has been set up for about a year but most of the corals in it are new (growing and splitting like crazy). IMO there is no need for a skimmer on a nano if you do weekly water changes unless you over stock it with fish! I have 7 sps frags and all are doing great, have great polyp extention, and great color pics dont do justice.