Make an Aquarium

Building your own tank is a worthwhile, cost saving, and interesting activity. It requires only some essential tools and a good sheet of glass or plastic; the other things are up to you and your imagination. What kind of aquarium are you going to design?


Choosing and Prepping the Glass

  1. Decide which aquarium size is fit for your needs. If you only have a few fish or a small tarantula, you won't need an aquarium that takes up the length of the wall. If you have a veritable pool of fish you need to house or a large iguana, that may be a different story. Since you're making the aquarium, you get to call the shots.
    • If you're placing water into the tank, remember that water is very heavy – about 10 pounds per gallon.[1] You may want to go on the smaller side just to keep it more portable. There are some neat calculators available online, too, if you're stumped.[2]
    • Aquariums can also double as neat tables or shelves. If that's the case, measure the area you want to place it in to determine the right size.
    • If you choose, for example, a 14" long aquarium, the sides should be around 13 1/2-" long to account for them fitting into the front and back pieces.
  2. Use annealed glass. This is also known as "plate" or "sheet" glass. Although annealed glass breaks into chunks and slivers, its superior strength makes it a good choice for aquarium building.
    • Do not use tempered glass (it usually has an identifiable etch mark in the corner). It is not strong enough. Laminated glass, toughened glass, and polycarbonate plastic are all other "okay" options, but they're subpar compared to annealed glass.
    • If only one side of your aquarium is going to involve glass, a combination of glass and fiberglass will work.
    • Upon purchasing your glass, ask the glass shop to sand or grind the edges so it doesn't end up cutting you.
  3. Choose the thickness of your annealed glass. If your aquarium is going to be full of water, you'll likely need to err on the side of caution and go with thicker glass. 12" full of water is very different than 12" not full of water. If you're keeping it empty, even up to 14" could be fine with {{safesubst:#invoke:convert|convert}} thick glass. Here are the general guidelines:[3]
    • Aquarium Height / Sheet Thickness
      {{safesubst:#invoke:convert|convert}} / 1/4 inch
      {{safesubst:#invoke:convert|convert}} / 3/8 inch
      {{safesubst:#invoke:convert|convert}} / 1/2 inch
      {{safesubst:#invoke:convert|convert}} / {{safesubst:#invoke:convert|convert}}
  4. Get the rest of your equipment together. You'll need:
    • 100% silicone sealant
      • Many people say that "aquarium silicone sealant" is the only sealant you should consider. Although it's rather expensive, it is a good choice, partly because it lacks anti-mildew chemicals often in standard silicone sealants that can be toxic to fish over time. Regular household silicone like GE Door & Window clear silicone, Dow-Corning "DAP", and Napa All-Glass 100% clear silicone are also viable options. And if it comes in the size that fits in your caulk gun, even better.
    • Masking or duct tape
    • A caulk gun
    • A few large containers or heavy objects for holding up the glass
  5. Arrange your glass pieces in an open area. Put the bottom piece of the glass down, surrounded by the front, back, and sides. Remember that the sides should be just shorter than the final measurement so they can snugly fit into the length between the front and back (those will go up first).
    • The difference in thickness should be twice the size of the glass. If you have 1/4" inch thick glass, your side pieces should be 1/2" in shorter (to account for the 1/4" on either side).
  6. Prep the glass. First, use acetone or rubbing alcohol on the sides of the glass. You want all the edges to be clean as can be. Then cut strips of masking or duct tape that are about half the length of one side. Stick half of each strip on the bottom of the bottom pane in every direction. The other half of the strip should be lying freely on the table.
    • Then when you put up the sides, you'll grab the other half of the strip and tape it on, giving support to each side of the tank.
    • You may want three pieces of tape on each side – on the left, right, and center of each pane.

Assembling Your Aquarium

  1. Apply the silicone. Start with the bottom piece, applying a thin and continuous strip of silicone along the top, about 2mm away from the edge (where the front pane of glass will rest on it). The strip of silicone should be about 3mm in diameter.
    • If you're not used to using a caulk gun, practice beforehand making even lines on something else, like newspaper or cardboard.
    • When you go to cut the top of the tube, aim for a 3mm opening to control the size of your output.
    • Be sure to work quickly; silicone sets in 2-3 minutes.
  2. Put the front pane in place. With the strip of silicone along the front edge of the base, place the front piece of glass into place, pressing it down firmly but gently. Hold it there briefly, adhere the rest of the tape up the sides, and it should stay up. If you're worried about it falling over, you can prop it up with a large container filled with water or some other heavy object.
    • Don't wipe off the excess silicone just yet. You can take care of it after it's cured.
  3. Begin assembling the sides. With your caulk gun in hand, run another thin line of silicone (again, 2mm from the edge), along the sides. Then repeat along the inside edge of the front pane (remember: the side pieces are fitting not only into the bottom, but sandwiched in between the front and back).
    • Press the first side piece into place, firmly but gently. You should now have one corner of your aquarium put together it.
    • Try to avoid realigning the piece – if you do, you could create bubbles in the silicone, leading to leaking later on.[1]
    • Repeat this for the other side, too.
  4. Finish with the back pane of glass. Now that you're getting the hang of the caulk gun, run your last 3mm-wide lines of silicone along the edge of the bottom pane (2mm from the edge) and along the inside edges of the back panel.
    • Press it firmly, yet gently, into place. Lift up the tape to support and prop as needed.
  5. Allow the silicone to dry and set. Most types of silicone dry within 24-48 hours.[1] It will harden even more as time goes on, so if you can resist, don't fill it with water for a good week or so.

Setting Up the Inside

  1. Test the seals. Before you go about assembling a masterpiece in your aquarium, it's best to see if your craftsmanship holds up. Fill the tank with a few inches of water. Let it sit a minute. If it doesn't leak, continue on with assembly.
    • If it does leak, empty the aquarium immediately. Let it dry, and then reseal the problem areas. You may also want to assume there are problems near the top too, and fix those as well.
  2. Set up a filter system if need be. If you're dealing with freshwater fish, you'll need a filtering system. The most common choices are undergravel filters or power filters and they're easily hung on the back of the tank.
    • If you're using an undergravel water filter, keep in mind the size of your aquarium. A large aquarium requires a large filter. The air pump needs to work for the entirety of the tank; not just the area it's immediately place in.
    • A power filter should circulate {{safesubst:#invoke:convert|convert}} of water per hour [gph] and per gallon of your tank's capacity. An {{safesubst:#invoke:convert|convert}} tank would need a power filter that can handle 40 gph.
    • Follow the specific instructions on your filter's packaging. Regardless of your model, do not turn it on until the tank is filled with water and ready to go.
  3. If necessary, add a heater. This goes on the inside of your tank and is usually attached with suction cups. It should be placed near the filter where water is constantly moving (so the temperature remains consistent throughout). Just like the filter, don't turn it on until everything is good to go.
    • Try to keep it to 3-5 watts of heat per gallon of water, in general. However, different fish do have different preferences; because of this, an adjustable, fully-submersible heater will be the easiest to use.
    • Remember that lights often produce heat and can interfere with your intended temperature. If this is an issue for you, there are lights available that don't heat up – and they're much better for fish.
  4. Fill your aquarium with gravel, sand, or whatever your creatures require. Most fish will be good with either gravel or sand, and any pet store will offer you a plethora of choices when it comes to texture and color. Whatever you use, {{safesubst:#invoke:convert|convert}} should be plenty.
    • Gravel does need to be washed before placing it into the aquarium. It has a tendency to acquire dust, which is something you do not want in your water.
  5. Add in a few inches of water (if applicable) and your decorations. Everything will be easier to place (and it will stay in place) if you work with a few inches of water in your aquarium. Hopefully this time there won't be any leaks! Adjust as necessary, accounting for the weight of the water where need be.
    • Once you have the terrain all set up, fill the aquarium all of the way up. Most people recommend a gap of about 1" or so from the top, though this is ultimately up to you – some prefer not to see a water line at all.[4]
  6. For freshwater fish, add water dechlorinator and cycle your tank. Fish do the opposite of thrive in tap water, thanks to chemicals in it like chlorine. On the dechlorinator packaging, it should tell you how much is appropriate to use for your size of tank. You may also want to use a bacterial catalyst like SafeStart, which will speed up the growth of good bacteria in your aquarium.
    • Once that's in, you'll need to do a fishless cycle to monitor the water parameters (pH, High pH, Ammonia, Nitrite, and Nitrate). Get an aquarium testing kit and wait for the numbers to spike and lower to 0. When this happens, it's time to add your fish.
    • An ammonia remover may be useful if the levels are too high. What's more, as time progresses, you should change 15% of the water routinely to keep it fresh and clean.



  • To protect the fish from their enemy (your cat), cover the upper part of aquarium with a plastic lid or wooden ply.
  • You can stick duct tape on the outer edges for more protection of the aquarium.


  • Don't completely cover the aquarium with a lid. Be sure the air can flow inside the aquarium space.If you do, drill/cut holes in the lid. The heat from the water and lighting should provide enough convection to create a good air flow.
  • Do not put the aquarium directly on carpet; mold can grow.

Things You'll Need

  • 5 sheets of annealed glass
  • Aquarium-safe Silicone
  • Cloth Gloves for handling glass
  • caulk gun
  • Masking or duct tape
  • Large containers for support

Related Articles

Sources and Citations