How to Build Acrylic Fish Tanks

Building your own aquarium with acrylic lets you customize the tank to suit your personal design and space specifications, and gives you freedom to integrate features such as sumps, overflows and fish hatcheries. Using tinted acrylic for the back panel allows you to add a unique background that enhances your design. Use only cell cast acrylic to build a fish tank. It is easiest to work with and won't melt during cutting.

Goldfish in water tank from a distance
Acrylic offers 10 times the strength of glass and less visual distortion.
credit: y_seki/iStock/Getty Images

Sketch out your aquarium design on graph paper and determine your dimensions. Allow an extra sixteenth of an inch on each side to allow for router finishing of the edges. Order acrylic sheets in the appropriate sizes from a local or online plastics supplier. Most places will cut your acrylic pieces to your specifications. When ordering, tell your retailer you are building an aquarium and you need the cuts to be as exact as possible. Don't forget to order the back panel in your desired color if you want a colored background.

Shave the edges of your acrylic pieces with a straight cut router bit for tight seaming. Use the C-clamps to affix a straightedge to your acrylic piece, which will act as a router guide.

Drill or saw any holes you need for plumbing. Use a hole saw or jigsaw for larger cutouts, misting the bit or saw blade with water while cutting to cool the acrylic and prevent melting. Even if you are using cell cast acrylic, cooling the cutting surface adds an additional layer of protection against melting the acrylic.

Assemble your aquarium, using masking tape to temporarily hold the seams together. Ensure that all of your seams fit together tightly. Choose two panels to begin welding. Build your sides first, then affix the entire box to the top and bottom.

Insert straight pins, such as those used for sewing projects, into the seam you're working on at intervals of 4 to 6 inches. This leaves just enough of a gap for your solvent to flow into the seam. Lay your seam horizontally to weld.

Load your syringe or solvent bottle with solvent. Gently squeeze the solvent into the seam, beginning at one end and flowing smoothly to the other end.

Wait 30 to 60 seconds, then remove the pins from the seam. This allows the acrylic to melt and begin to weld without becoming too stiff to fill in the pin holes. Allow the pieces to sit for about four hours before welding the next seam.

Repeat the welding process until your aquarium is complete. Sand off any rough edges and round off the corners using 200-grit sandpaper. Allow the tank to cure for at least a week, preferably up to a month, before adding water.