You can easily design a DIY sump to improve your aquarium. Although sumps aren't essential in most aquariums, they will improve the appearance of your aquarium by keeping all of the equipment separate from your fish. The sump also provides a good location for adding more water to your aquarium or for introducing chemicals.
To construct a DIY aquarium, you must gather several materials. The most important piece of the sump is the tank. You will need a 10 gallon or larger aquarium tank to use as the framework of the sump. You also need Plexiglas or clear acrylic to use as dividers in the sump, silicone sealant, filter media, a drill that will work with Plexiglas or acrylic, and a tool for cutting Plexiglas or acrylic.
Constructing the Sump
Cut a piece of Plexiglas or acrylic to a width that will fit snugly in your tank and a height of 1 inch less than the tank's height. This piece will serve as the main divider in the tank, separating the tank into two sections. One section should be roughly twice as large as the other, but this does not need to be exact. Slide the divider into the empty, dry tank so that it is flush with the tank's top, and a 1-inch gap remains between the divider and the tank's bottom. Secure the divider in place using silicone sealant. You may need to hold the divider in place while the sealant starts to try. You can also place a 1-inch-tall object underneath the divider to keep it from slipping down before the sealant dries.
Next cut two pieces of Plexiglas or acrylic to fit horizontally in the smaller section of the tank. One of the pieces should fill the full length and width of the tank section, and the other should be the full length but an inch shorter width. Use silicone sealant to attach the smaller piece of Plexiglas or acrylic 2 inches from the bottom of the tank. Then place your filter media on top.
Drill about 20 small holes in the second plate. Then attach the plate above the filter media using the silicon sealant. This plate will help water slowly trickle into the filter media.
The final step in constructing the DIY aquarium sump is to add a water return pump to the larger chamber that sends water back to your main aquarium tank, and to add a water pump to your tank to pump water into the smaller chamber or the sump.