G4 CubeQuarium 2.0 - The Build

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About 6 months ago, I randomly purchased a G4 Cube enclosure from eBay. It was on sale for $30 since it was pretty banged up, but I saw lots of potential in it. It stayed in storage for a few months since I had no idea what I could do with it, but one day I stumbled upon a website that built an aquarium out of the same shell (http://home.comcast.net/~jleblanc77/cube/). So drawing inspiration for that tutorial, I decided to convert the Cube into a kickass aquarium to complement my current 30 gallon fresh water aquarium.

Given the small volume of the Cube (about 1.2 gallons), I knew that unless I added some filtration and aeration, I’d be limited to say a Beta fish or a couple of Goldfish. So I took a quick trip to the local Aquarium store and I found various parts suitable for a nano-aquarium. Then, after some brainstorming and sketching, I designed my dream CubeQuarium with the help of a friend and we finally got around to building it.


Thanks to the excellent tutorial found at http://home.comcast.net/~jleblanc77/cube/, building the base was pretty easy. You can see pictures and more details about the construction there.

Cutting the base

For the base, I bought a sheet of 1/4” plexiglass at Home Depot and then cut it at home using a table saw. I’ve tried cutting plexiglass before using a jigsaw and a dremel tool and both give decent results but take a long time. Here’s my suggestions on how to cut acrylic using the different tools.

  • Dremel tool: While time consuming, it’s possible to cut using the cutting tools offered. I have this set Dremel Cut-off Wheel Set and I use the bigger wheels. The trick is to cut through the sheet from top to bottom without moving the tool laterally. Think of drilling through the sheet with the cutting bit instead of cutting it with scissors by dragging the dremel along. Just be patient as it can take a long time.
  • Jigsaw: The problem I’ve had with the jigsaw is that the plastic melts easily and then bonds back together behind the blade. I actually cut a whole 2 foot sheet once only to realize I had to do it again since it was all melted together. However, I found an excellent trick to prevent this from happening and it’s to use one of those pressurized air cans to cool off the plastic instantly. Just spray it upside down so the liquid comes out around the jigsaw and the plastic will cool off. Not sure how good this is for the blade, but the amount of time it’ll save you is probably worth it. It helps to have another person do that while you cut across. Make sure to use a wood cutting blade with say, 10 teeth per inch.
  • Table Saw: My tool of choice. Easiest way to cut acrylic in my opinion. The trick is to get the right blade for the job. For my 10” table saw, I used a 60 tooth saw blade like this one to cut through the sheet. The blade height should be set slightly higher than the acrylic sheet to minimize friction between the blade and the sheet. Doing that, I got beautiful, smooth cuts time after time and in seconds instead of minutes.

Mounting the base

Mounting the BaseOnce I finished cutting the base, I rounded off the edges using a dremel tool with a sanding bit. One important detail I noticed is that the cube edges taper as they are thicker at the top than at the bottom so you have to trim down a bit more than the opening at the base leads you to believe.

Finally I mounted the base. The only difference is I put the nails below the aquarium base rather than through it and added a couple more for extra support. The reason for that is my drill bits kept shattering the 1/4” plexiglass so I opted for this other method. Once that was done, I placed the silicone seal around the edge and had a couple rounds of testing to see how well it held up.

Attaching the filter

Attaching the FilterThe top of the Cube doesn’t allow for much mounting so I had to do what I dreaded doing all along and that’s cutting through the actual enclosure. Luckily, one of the top openings in the cube was perfect for mounting the filter. To cut it, I simply used a combination of the dremel technique along with the jigsaw. It was a tough, messy cut, but since the filter goes over that it really doesn’t matter what it looked like. Once cut, the filter dropped in perfectly like it was destined to go there. Even the filter tube and the water cascade fit the aquarium well and cause no trouble.


After the leak tests, I was ready to decorate the CubeQuarium. Because of the small size and the small opening on the top, my decoration choices were limited. I knew from the start that I wanted to get some gravel, lots of plants, and a couple of air-stones but I didn’t think I’d be able to get a decorative item. After a bit of browsing at the store though, I managed to find a nice little roman ruin piece that actually fit through the opening. So with all those pieces in hand, I got around to the final build.

Attaching plants and air stones

Attaching the Plants

My first task was to get the plants and the air stones set up around the base to then build a layer of gravel over them. The plants had a little base that you can fill with gravel and they’ll stay put pretty well. For the tubing, my technique is to use as many suction cups as needed to keep everything in place. Everything was done through the opening up top which proved to be moderately difficult. Patience is key to this step. I also got a 2 slot gang valve for easier tubing mounting and to control the back and front bubbles independently. (Yes, I know I go overboard sometimes).

Gravel, decorations, and finally… fish!

Gravel and Decorations

Finally Fish

Next, I just filled up the tank with enough gravel to cover the tubing and the air stones. Then I placed the decoration on top. I used to dig it in a little bit for stability, but since I have to work with this aquarium a lot more than usual and the ruins decoration takes up so much space, I wanted a quick way to remove it. It’s stable enough on it’s own anyway.

Finally, it was time to fill it up and toss in my new residents. I added water to the tank by filling up the filter and letting it overflow into the tank. This way there was minimal disruption to my decorations which took so long to set up. I decided to get a couple of Neon Tetras and a Golden Algae Eater to test out the aquarium with. Don’t worry, after a short quarantine period they will soon join their pals in my larger aquarium.


Three days and $150 later, my CubeQuarium is done and working wonderfully. I was optimistic about how many fish I could fit in there when I started, but now that it’s done, I can see how small the tank really is. At most I can probably keep 2-3 small fish so I might just keep it as a quarantine tank for my main tank. I saw some fluorescent tetras at the store which might be cool here too. Anyway, be sure to hit up the photos page to see bigger photos of the build process and of the completed tank. Enjoy!

  • Leanne

    I love the idea, but am having some trouble viewing your photos - any chance you could please take a look? I'll try back later in case it's a temporary thing on my end. 

  • mitch rusch

    Choosing right and beautiful aquatic plants will help to make the aquarium design beautiful.

  • Nhan Phan


    i'm working on a G4 cube fish tank as a birthday gift for my wife. since i dont have much time to pick up the parts for it, so ask a friend of mine (he works at a window store) to cut for me a sheet of Acrylic with the dimension of 1/4" x 7 1/4" x 7 1/4" and the 4 corners of sheet has a curve of 1.5" in diameter. i don't know if the dimension above is correct for the bottom of the tank but i've tried my best to measure it. if you still have the dimension for the bottom piece of the tank, would you mind sharing them to me ? . this cube would be an excellent gift for my wife. thanks

  • Awesome aquarium ornaments. Creative design like an Apple logo.

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