The tank was around 4 years old when we finally took it down. We knew that we would be moving out of state and that the move itself would be too hard on the coral to survive. Because there were so many variables involved with the move from Washington to Colorado, we thought it would be best to be proactive. Finding new homes for all of the coral and fish took months. We wanted to make sure the prospective new homes would be able to provide the lighting, chemistry, and flow needs of these delicate corals.
You can read more about this project at: reeffrontiers.com - "Halmus' 120 Reef Tank" Most of the filtration for the 120g system was built into the closet behind the aquarium. There was quite a few holes to fix in the drywall after tearing down the aquarium. I built all of the sumps from acrylic custom to fit perfectly in the space available. In the space is the main sump on the bottom. That contains the refugium for macro algaes to grow out. The protein skimmer is also down there and a float valve for fresh water top off. I typically lost 1-2 gallons of water a day from evaporation. The middle shelf held the extra sump as a grow-out section for coral fragments and the chiller to keep the tank from overheating. The top shelf eventually held an additional 24" x 24" shallow frag tank as well as a 20g tank for mixing fresh salt-water for water changes. I made the sliding doors from parts of louvred doors I had around. They kept the daylight out while allowing the system to "breath" a little.
This is a closer look at the chiller section and another sump that was underneath the aquarium itself. It was a deep sand bed filter with another breed of macro algae and mangroves. I'm not sure it did much good for filtration, but I love the diversity in the system. The third picture is the control box I built that was connected to an array of float sensors in the fresh water reservoir used to replenish evaporated water in the main tank. I could turn this on whenever I needed to get an idea how much fresh water I had left.
The fresh water reservoir was a 40g tank that I built into the attic. I had to build a platform for it in the rafters. This allowed me to have more fresh water on hand without having a large tank taking up space in the house. My wife already let me have the closet, she wasn't going to give up the rest of her work-out room. The RODI unit was in the garage that sent the water supply up to the attic through a 1/4" airline hose insulated within a 3/4" PVC pipe. I also had a heater and circulation pump that would turn on if the water temperature got below 50deg.
For control of the system, I used an Apex Neptune system with four energy bars (8 outlets controllable each). I also made good use of the additional logic interfaces to hook up water sensor circuits to detect any possible disasters in progress. I also used the logic interfaces to detect float switches. Through the code, they would turn off pumps if water levels ever got too high due to clogged drain pipe. Also, I used an array of float switches on the fresh water tank to allow me to check approximate water levels since it was not easy to check on in the attic. Temperature of the main tank, the fresh water tank, and PH of the aquarium were also monitored through this system. For those of you not aware of the Apex System, they provide a web interface that allows you to remotely monitor these levels, the state of outlets, and program in your own custom code to interface all of the switches and lighting cycles together. Because the controller was a big investment, I shielded it behind an acrylic enclosure to protect it from splashing water. I also had an UPS on it along with my modem so that I could receive email notifications when the power was out.