How Build Your Own Acrylic Aquarium
Let's get going with our DIY aquarium. As with any aquarium set up, the first step is deciding what kind of critters you want to incorporate in your tank - and how many. This is very important as it will decide what size you need, and how much it will cost you in the long run.
As a general rule of thumb most people will say one gallon per inch of fish, at minimum, for fish under 3 inches. 3 gallons per inch for fish over 3 inches. We're going to assume we want to build a 120 gallon tank with dimensions of 48x24x24, in inches. I will leave this for you to decide. With some simple math you can play with the size and adjust the volume to your needs. The tank I built for myself is 50 gallons.
Once we know what size we desire, we need to find our resources for the build. Here is what we will need-
- Acrylic Sheet(s)
- Small aluminum angle irons (1"x1"xdesired perimeter for top AND bottom) for top and bottom support rims
- Weld-On brand #4 Solvent Cement
- Aquarium safe silicone
- Solvent bottle
- A few 1x4s
- Duct tape
First we need supplies!
Most plastics suppliers will stock acrylic sheets 4'x8'. One sheet is perfect for our build, as every inch of the sheet can be used with none left over, with no more extra needed. Be sure to get cell-cast acrylic, as other types will not work; the seams and often the sheets themselves will be too brittle and fail - not a fun time.
When you order your acrylic, ask if the price will include cutting, if not, pay the extra - acrylic is extremely hard to cut in a perfectly straight line by yourself. I would also recommend asking if they can route the edges smooth for you, as this will make your job a whole lot easier and give you much smoother surface to adjoin. While you're at the supplier ask if they have any scrap pieces they're throwing away, they don't need to be big at all, just something to practice gluing and assembling with. As with anything in life, it is always good to practice a bit before the big game.
Acrylic thickness is extremely important, and varies per build. The length of the tank will not be the deciding factor, not the volume; however the height is the big factor here. For a tank from 0 to 12 inches tall I would use 1/4" thick acrylic, for 13-19" I would use 3/8", and from 20-24" I would use 1/2". Obviously, we could go taller and as a result need thicker acrylic, but let's not go there for today. Expect to pay $160-$200 for a 4ftx8ft sheet of 1/4" acrylic, $250-$350 for a 3/8" sheet, $350-$450 for a 1/2" sheet.
Practice makes perfect!
Remember the scrap I mentioned earlier? This is where it comes in. This is not absolutely vital to the project, but it is definitely a good idea to practice smoothing and joining with some scraps before you do it on the real thing. Joining acrylic is not like gluing the macaroni on construction paper like we did back in the day, take a minute to practice and get it right.
Okay, got everything? Good, next step!
You will notice your acrylic will have a protective film on it. Do not remove this, as it will prevent the solvents from staining the acrylic where the solvents don't need to be. Instead, leave it all in place, except for a sliver you cut away, about 1", around all sides.
Now do a test fit and make sure all of your panels fit up 100%. Be sure to check for any gaps between all surfaces. This is extremely important, because if there are any gaps you will have a weak spot that will eventually break down and cause either a leak or a massive and horrible failure. Also, during this step I would recommend checking every edge thoroughly for any abrasions or burrs. If you didn't or weren't able to have the edges routed by the supplier, you will have little saw marks over every edge. These need to be smoothed out as much as possible to provide the best adhesion and seal. I've found a 2 flute-straight-cut router bit (used by hand) works well for this.
After you've scraped the sides smooth, we can now join the pieces. Lay the pieces in the fashion you want to adjoin them. It is very important you don't apply too much pressure on the pieces, as the solvent will not be able to penetrate the joint properly. Once the pieces are laid out the way you want them adjoined, use your solvent bottle, or even a syringe, to run the solvent cement along the joint, until you see that the joint is 100% penetrated. Since acrylic is transparent you will actually be able to watch the solvent run into the joints. Only do this process once, as adding more will weaken the joint.
- Lay a support for your bottom plate, I like to use a few 1x4s. Lay your bottom plate on the 1x4s.
- Add strips of duct tape, roughly 6 inches long, every 5 inches around the plate, from the bottom side (Half adhered to the plate, the other half hanging, adhesive side up.)
- Have a friend help you set the sides up in place on the bottom plate. Use the tape from step 3 to hold the sides on the bottom, and also put a few pieces on the sides to hold them together.
- From the inside of the tank, run your solvent cement along only the bottom edge. Apply solvent only on a horizontal plane, as it will not penetrate the joints if you do it vertically.
- Let the tank sit for 4 hours. It is extremely important that you do not move it!
- Now, the bottom has sealed and cured, you can do each corner. Flip the tank to its side, now you have two corners on a horizontal plane, run your cement.
- Wait 4 more hours. Again, be extremely careful to not move it.
- Once the side you just did is ready, flip it over to the other side and repeat the process.
- And then, another 4 hour wait.
- Now that your tank is all assembled and cured, run the aquarium safe silicone sealant along all joints to ensure a good, safe seal.
- Now the angle irons come into play. Cut them to length and miter the joints. If you know someone who can weld well, have them weld the angle irons into rectangles for your top and bottom supports, you can grind the welds down to a flat and smooth finish for style. If you don't know a welder you may need to join them with metal adhesive available at your hardware store. I was careful to cut mine exact enough that they almost snapped right onto the tank, I used some of the silicone as a glue to keep them on the tank snugly.
Now you have a brand-new aquarium! The next part is to find or make a hood (I'll leave this up to you,) get your accessories and fill her up!
Don't forget to cycle the tank before adding your fish!