My Custom Split-Sump 50 Gallon Reef Tank

The Build was certainly learning experience – one I’m still learning from. I started by first buying an aquarium stand that looks good and would fit the room nicely – first mistake. although it looked nice, it quickly realized it was not designed for the type of system it was going to have to house for a successful reef tank.

The system was going to need a sump -ideally, a sump that could hold both the mechanical filtration (protein skimmer) as well as some sort of refugium for  growing macro algae and housing extra live rock. The stand had two cabinets on either side – neither of which would be enough room for the sump.

an early version of the design

I came up with the idea of doing a split system; two sumps – one on either side. I sketched it out and it looked good on paper. So, i set out to do a virtual mock up to see if it would work.

Near final design – still have a few flaws that i would work out later

I went through lots of different designs and variations, asked hundred of questions at my local fish stores (I’m sure they got tired of me), and posted messages on user boards. nearly everyone told me that my designs where way over complicated and that i should just buy a simple stand that was designed for the purpose. Probably good advice, but i figured, “what fun is that?”

Once I had the basic concept down, I needed to design the sumps. This was probably the most challenging part of the design process.  Each sump had a specific purpose, and need to house specific equipment in vary limited space.


In addition to housing the equipment, they would also need to be big enough to handle the overflow water from the display tank in the event of a power failure. Basically if the power fails, the pumps turn off, When that happens the water will continue to siphon from the display tank into the sumps until the water level in the display tank reaches the top of the return line.

once I had me sumps built, I performed a few tests. The first was a proof of concept test. basically setting up the sumps outside of the stand without much plumbing.

The second test was after everything was built and setup. This was the last leak test before moving the tank into the house.

In the end – the tank worked exactly as planned and achieved all my goals, which where:

  • Setup and Create a successful tank.
  • hide as much the equipment as possible  – while the cabinet was closed, you could not see any thing other than the overflow and lights.
  • create a design that was both functional as well as interesting to look at. I loved seeing the look on peoples faces when I opened the cabinets to reveal all the inner workings. Most did not expect to find so much going on below the tank.

I ran this tank for about a year and half until a we decided to upgraded it to a 125 g. Below are a set of photos documenting the final build before I put water in it.