Since I have been getting sooo many questions about my set-up, I thought I would break it down and maybe it would help... First of all, I would probably be considered an advanced aquarist. I have worked at several public aquariums as both an aquarist and educator. While I was in graduate school, I worked at the Waikiki Aquarium as an aquarist. I have set up small and large aquariums. The smallest would be my 10 gallon freshwater frog tank and the largest would have been my 8 foot diameter cuttlefish tank on the grounds of the Waikiki Aquarium. I have no idea how many gallons that would have been, but it had fresh sea water flowing in and out at all times, so that was probably my easiest tank! Besides knowing basic tank maintenance, I can repair most of my equipment, or know when it is too far gone to repair (like the time I caught the protein skimmer on fire...). That said, I have a 55 gallon that currently houses two male Sepia bandensis. I purchased this tank from a person who was raising mushroom corals and zooanthids, along with couple of fish. The reason I was interested in this tank was, it had already been running for several years (and was already cycled) and it was the size I was looking for. I only had to dismantle the whole thing at his house, transport it to my house and take each piece up the 34 STEPS to my basement. Can I just say, live rock is heavy!!! I added fresh sea water made with RO/DI water and waited for the mini-cycle. Once it was stable, I transferred the cuttlefish from my 29 gallon tank. Ok, so here are the components of my tank... 1. 55 gallon tank with overflow in the corner. Basically there is a piece of plexiglass in the corner of the tank and it has slits at the top of the plexiglass. The water flows through the slits and down a tube with a float inserted into the tube. If the water level gets too low, the float blocks the flow of water into the tube. This is so that 55 gallons of water does not end up in my sump and on the floor... 2. Live rock - at least 55 pounds of live rock, covered with coralline algae. 3. Prefilter - once the water goes through the overflow tube, it goes through a piece of foam and some bioballs. 4. Sump/Refugium - probably about 15 gallons, but not sure. After the prefilter, the water flows into the sump/refugium. This is filled with about 1 1/2 inches of miracle mud, and some green algae. Some is chaetomorpha, I have no idea what the other stuff is... 5. Wet/dry trickle filter - after the refugium, there is another chamber with bioballs that the water overflows into (kind of like a waterfall) 6. Pump - I have a QuietOne and it is anything BUT quiet. Once the cuttles pass on to the ocean in the sky and am replacing it... 7. Protein skimmer - my protein skimmer is rated to 150 gallons. I could not fit it in the sump or I would have. It is currently hanging on to the back of the 55 gallon tank. 8. Even with this filtration system, I still do water changes, every week or every other week. Hope this helps... Remember, this is only ONE way to do this, even if you replicate my system exactly, you may not have the same results that I have had. I have years of aquarium experience that also help me, plus, I have one of those "salt-water thumbs" like Thales . When I have time, I will post pictures of the various parts. Also, if I were to have built this system myself, I am not sure I would have included all of these parts (the live rock and protein skimmer for sure, but there are many ways to filter a tank...). Good luck!