DIY Glass Sumps

As someone who has made a few glass sumps, and one fully customized acrylic sump, I don’t get the excitement over acrylic sumps.  Glass sumps are cheaper, easier to build, and hold up to abuse better than acrylic for the average user.  I buy non-reef-ready aquariums at the local pet store $1/gallon sale, design the sump, and then get some glass cut.  This is how I made a 40g glass sump for $65.

Start with a pre-built glass tank.  It’s easier that way.

40 gallon glass sump – used for $35

Design the setup.  Keep in mind you’ll need to account for the water that overflows from the main display aquarium drain into the sump.  Leave enough space for that water plus a few extra gallons just to be on the safe side.  I like to stay simple with sump designs.  The water drains into a filter sock, into a skimmer, through some baffles (to help minimize the bubbles from the skimmer), slowly over a refugium, slowly over a deep sand bed, through more baffles, to the return pump.

Once the design is complete, measure the pieces of glass  you’ll need.  If your local glass shop will let you (and if the tank is small), take the tank with you so the glass company can custom-fit the glass to the tank.  Tank sides are rarely truly parallel, so the baffles may need trimming.  I also recommend having the glass shop sand the edges of the glass to prevent injury during installation.

These baffles cost $20 – custom fit and sanded
Use a high-quality silicone made for aquarium use.  I chose black for the sump, but it is also readily available in clear.  Do NOT use bathtub silicone as it frequently contains an anti-mildew chemical in it that can foul an aquarium.  Home improvement stores often carry the AllGlass brand, and local fish stores often do as well.  Use only in a well-ventilated area as the fumes are not pleasant and may cause health problems.
I used less than half this tube for the project – $10
Use a measuring tape and right angles to place the first baffle.  Work the smallest areas to the largest areas to prevent areas that are difficult to seal.  I worked on the left, right, then center.
Right angles help in properly aligning the baffles – $0 (on hand)

I use duct tape to hold the baffles in place while it dries.

Lastly, place the filter sock holder, if desired.

The finished project!

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