After much debate about our space limitations we have decided to go with a bioCube 32 for our first saltwater tank. They make a protein skimmer that fits in the back of the tank, do I need this piece of equipment for this tank? It will have live rock and sand, 2 clown fish, maybe 2 other fish that would work with this set up (not all at once) and some invertebrates. I am also wondering about a small power head. Thanks in advance.