Acrylic Fishtank DIY: Step by Step & How To Build

If you’ve ever dreamed of building your own aquarium, an acrylic fishtank DIY project is a good way to get started. Many fish lovers begin with glass tanks, but building your own acrylic aquarium has some major advantages. Acrylic sheets are easier to work with, lighter to handle than glass cages, and give you more design options if you need a custom tank of that size. Whether you want a small display tank for your living room or a larger tank to fit into such space as a converted phone booth (like ours), this guide walks you through the building process in detail.

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En Nuestra Casa

Have you ever heard the story of our phone booth fish tank? If not, catch yourself up by watching this quick video.

What you might not know is that the first iteration of our phone booth fish tank was what I like to call Peterson’s “colic project.” (We suffered through six weeks of colic with our second baby, and we each found some sort of outlet to make it through some very difficult days. I built a business, Peterson built a fish tank, haha!)

The first round of our acrylic fishtank DIY was cute and functional, but we’ve been wanting to rebuild it to make even better use of our phone booth space. And that’s where this project was born! We’d still love to go even bigger and better one day, but for now we’re really pleased with how this project turned out.

If you’re even remotely interested in a simple box aquarium project or want a very specific size of the fish tank, keep reading to see how you can make one of these acrylic aquariums yourself!

Why Choose Acrylic Instead of Glass Tanks

The main reason we switched from glass to acrylic was the ease of use. Our first attempt with glass required masking tape, silicone, and even a glass cutter. We posted about it on an old thread, and if you ever stumble on that older thread, you’ll see why it didn’t hold up. In contrast, acrylic glue bonds clear acrylic sheets in minutes. No tape required.

Another good idea is to use cell cast acrylic instead of extruded. This type has a high strength value, making it the ideal material for a tank of that size. Plexiglass fish tanks are widespread, but for our build we avoided plexiglass since it’s more expensive and not necessary for simple box aquariums.

Planning Your Acrylic FishTank DIY

The planning phase is everything. Before cutting or bonding anything, measure the exact size you want. For us, the dimensions of the fish tank were dictated by the phone booth’s unusual interior space, which included a two-inch curved section at the bottom. We had to create a support block and base before starting the tank.

Sheets of acrylic can be ordered pre-cut, which is the ideal choice if you want clean edges. Buying a plastic glass sheet and cutting it yourself might seem like a good way to save money, but without proper tools and grit paper sanding, it’s easy to chip the edges. Pre-cut acrylic gives you perfectly square side pieces and front panels, which makes the assembly process much easier.

Materials for an Acrylic Aquarium Project

Here’s what we used for this project:

• Pre-cut clear acrylic sheets (3/8 inch for sides and bottom piece, 1/2 inch for the lid)
• Acrylic glue (Weldon 4 or Weldon 16 depending on curing time preference)
• Straight edge or carpenter’s square for alignment
• Soft cloth and grit paper for cleaning edges
• Wood for the support block and base
• Jigsaw or Japanese pull-saw
• Paint and sealant
• Sandpaper for smoothing the platform

The Building Process: Creating a Base Platform

Because the phone booth has curves at the bottom, our first step was to create a base. Without it, the tank wouldn’t sit level on the edge of the surface inside the booth.

Here’s how we created a simple wooden base:

1. Cut wood to size, leaving enough space in the back for the lip.
2. Glue and clamp the wood until dry.
3. Use a jigsaw and grit paper to refine edges until it fit.
4. Dry fit the whole film of pieces to confirm they lined up.
5. Paint it black and seal it.

With the platform done, we could start the acrylic tank itself.

Step by Step DIY Acrylic FishTank Assembly

The assembly is straightforward but requires patience:

1. Lay the back panel flat.
2. Attach the side pieces to the back with acrylic glue. Some people use the pin method, but we found it tricky to keep square. Using a straight edge worked better for us.
3. Attach the front panels to the sides.
4. Place the bottom piece last, bonding it to all four walls.
5. Run a light bead of acrylic glue along the interior seams for reinforcement.

Compared to working with glass tanks, the difference was striking. No masking tape, no silicone, no waiting days for it to cure. The whole building process was smoother and cleaner.

Final Step: Cure and Leak Test

Once assembled, leave the aquarium to cure for 24–48 hours. Then comes the all-important leak test: fill it with water, let it sit for another 24–48 hours, and check carefully. This final step is the only way to ensure your beloved pet fish won’t end up swimming in your living room by mistake. Good luck — but honestly, if your seams are clean, you’ll be fine.

Design Options and Lessons Learned

Through trial and error, we learned a lot:

• Thicker material isn’t always better. A half inch sheet is great for the top of the tank, but 3/8 inch works perfectly for side panels.
• Always leave enough space for water changes. We planned our lid so we could reach inside easily.
• Keep the protective film on until the end to avoid scratches.
• A frosted back panel can simplify the look and make your display tank the perfect focal point in your living room.
• Bow-front tanks may be popular, but we don’t love them. A simple box has a cleaner, timeless look.
• Custom tanks are an option if you want curves or unusual shapes. But for most fish lovers, building your own acrylic aquarium is the ideal choice.

Cost of Materials

Our material cost was about $150 for all sheets of acrylic plus cement. While you could cut a plastic glass sheet yourself, pre-cut dimensions save frustration. Considering how much large tanks or custom tanks cost in stores, an acrylic fishtank DIY project is both budget-friendly and rewarding.

From Four Gallons to Ten

Our first acrylic fishtank DIY was a small four-gallon aquarium. It worked but didn’t maximize the interior space of our beloved phone booth. For our new thread of this project, we scaled up to a 10-gallon tank. The larger tank fits beautifully in the booth and looks much more balanced. The thicker material we used for the lid prevents warping from the light, which was a main reason we upgraded.

Would We Build Another Acrylic Aquarium Project?

Yes — in fact, we’d love to tackle a larger tank one day. Even though plexiglass fish tanks have a widespread use, and some fish lovers swear by them, our experience proved that cell cast acrylic is the ideal material. For now, we’re enjoying this tank as the perfect focal point in our quirky phone booth space.

Conclusion

An acrylic fishtank DIY may seem intimidating, but it’s really just about following a building process carefully, using the right acrylic glue, and making sure the final step — the leak test — is successful. If you’re looking for a good way to combine craftsmanship with fishkeeping, creating your own acrylic aquarium is both satisfying and practical.

From side pieces to the bottom piece, every panel comes together into a custom tank that will house your beloved pet and serve as a beautiful display tank. With patience and planning, you’ll not only save money but also gain the pride of knowing you built the aquarium yourself.