I’ve seen some really nice and very creative sumps. However, most of these are meant to maximize a very limited space under the display tank. With such a large stand for this build, space isn’t really the primary consideration and a lot of the creative solutions don’t really apply.
I came up with a fairly basic design.
The compartments in order from left to right are:
• In – This is where water will enter the sump. The baffle will reduce turbulence before it enters the skimmer chamber.
• Skimmer Chamber – I designed it to be large enough to hold two skimmers. I will likely start with just one, but may add another.
• Frags or refugium or both
• Return (evaporation occurs here) – Live rock rubble.
Bulk Heads
• The two bulkheads in the first chamber are intended for a closed loop between the sump and my water room. More on that later.
• The two bulkheads in the last chamber are intended for dual return pumps.
Water Volume – Pumps Running
Note: I’m not concerned about precision here – numbers are rounded for glass thickness and to error on the side of safety.
• (7 x 10 x 24 / 231) + (18 x 9 x 24 / 231) + (27 x 8.5 x 24 / 231) + (12 x 7.5 x 24 /231) =
• 7.273 + 16.83 + 23.84 + 9.35 = ~57 gallons
Water Volume – Total Capacity and safety considerations
Total volume is: 65 x 24 x 16 / 231 = ~108 gallons
Free space = 108 – 57 = 51 gallons
1” of water in the display tank is: 36 x 72 x 1 / 231 = 11.22 gallons
I should be able to accommodate for 4 inches of water back siphoning from the main tank.
(50 / 12)
Water Volume – Return Chamber
This is important at it effects the time before disaster in the event that all of the ATO systems in place fail. If for example the ro/di reservoir runs dry, water will evaporate from this section of the sump until the pumps run dry.
• 1 inch in this chamber holds 1.25 gallons of water: (12 x 24 x 1 / 231)
The pumps will start sucking air when the water level reaches about 3.5 inches. Therefore, I safely have about 4 inches to work with or 5 gallons of water. The rate of evaporation will be dependent on the amount of evaporative cooling required. I would estimate this at somewhere just short of 24 hours.
I considered a down turned elbow to bring the pump intake to about 1” from the bottom. The benefit being increased water volume at the cost of increased flow resistance. I probably won’t do this.
Guiding Principal
The main consideration with the sump was flexibility. I find it very hard to plan everything without the spatial benefits of seeing the space available. The sump should be usable in ways that I hadn’t originally considered. Suggestions are welcome?
Last Minute Modifications – The builder offered to drill a second hole in the first chamber (IN). I’m not sure it was necessary, but I figured it couldn’t hurt. If I don’t use it, I can always plug it with a bulkhead and some plumbing. Also, the two holes drilled in the last chamber (return) were too close together, so I had a third hole drilled. I will cap the middle hole or possibly use it as a drain.