How to Build a Bottomless Aquarium

Prepare Your Materials

• 1

  Decide what height you would like for your bottomless aquarium. Part of the appeal of a bottomless aquarium is watching the fish swim above the level of the lower aquarium. However, an aquarium with sides taller than 14 inches will require thicker walls than a shorter aquarium, thus adding to the expense its construction. Write down the dimensions of the two long sides, short sides and top of the aquarium.

• 2

  Purchase glass of the appropriate thickness and dimensions from a glazier or professional glass cutter. Request the sides to be prepared with mirror finish edges. This kind of finish will prevent you from accidentally being cut by the edges during assembly.

• 3

  Poke a small hole through the Styrofoam, just large enough to feed the tubing through. Secure the tubing to the Styrofoam so that it cannot be removed easily. Avoid restricting the air flow when you do so.

• 4

  Cut or tear eight 6-inch pieces of tape.

Aquarium Construction

• 5

  Center the two glass blocks in the bottom of the 20-gallon aquarium. The blocks should stand on end and should be close enough together to place the upside down portion of the aquarium on top of them. The wide face of the blocks should face the narrow ends of the aquarium. Glue the blocks in place with the silicone sealant.

• 6

  Put the aquarium stand in its permanent location. Place the 20-gallon aquarium on the aquarium stand.

• 7

  Clean the pre-cut glass pieces of any smudges and fingerprints before assembling them. Do not use chemical cleansers to clean them, as doing so can poison your fish.

• 8

  Cover your work surface with the cardboard or newspaper. Place the glass sheet that will form the top of your bottomless aquarium on the work surface.

• 9

  Apply silicone sealant to the top piece. The sealant should be applied in a solid ribbon about 1/2 inch from edge of the glass. Use your index finger as a guide, if needed, to aid in equal distribution of the sealant.

• 10

  Select one long side sheet of glass. Apply sealant in a single, smooth ribbon to the vertical edges of the glass, about 1/2 inch from the edges.

• 11

  Place the long sheet of glass along one edge of the top pane, fitting it onto the ribbon of sealant. The sealant that has been applied to this sheet of glass should face what will be the tank interior. Hold this pane in place with one hand. Tilt the top of the pane away from the center of the base.

• 12

  Pick up the first side piece and position it on the sealant that was applied to the top pane of glass. Hold this piece upright.

• 13

  Have your assistant position the second side piece on the sealant that has been applied to the top pane. Ease the long pane into vertical position. When in place, the three-sided structure should be free of gaps or protruding edges. You should now have a three-sided box. Ensure that all sides are flush with each other before continuing with assembly.

• 14

  Apply a single, smooth ribbon of silicone sealant to the vertical edges of the remaining glass pane, about 1/2 inch in from the vertical edge.

• 15

  Seat the final pane on the sealant that was applied to the bottom pane. Tilt the top edge away from the center of the aquarium, as before. After the pane is in place, tilt the final pane toward the center of the aquarium until it is snugly in place against the end pieces of your aquarium.

• 16

  Apply a piece of tape across each corner, near the top of the aquarium, ensuring that the two panes are flush and pressed firmly together. Check each side for any gaps between the vertical edges. Apply the remaining pieces of tape across the corners near the bottom of the aquarium.

Detailing

• 17

  Remove surplus sealant deposits that may have developed along the exterior seams between the joined panes of glass. Run a finger along each edge to determine if the panes are aligned correctly. Realign the sides as necessary.

• 18

  Remove surplus sealant deposits that may have developed along the exterior seams between the joined panes of glass. Confirm that the panes still are aligned correctly. Adjust as necessary.

• 19

  Apply fresh sealant to the interior tank seams, along the inside edges and corners. Smooth out the sealant in the form an arc using your finger or a rounded tool. Remove any excess sealant.

• 20

  Apply fresh sealant to the exterior tank edges and corners, along the joints. Smooth the sealant with your finger. Remove any excess sealant. Adjust panes as necessary. Allow to dry for two days.

• 21

  Apply a ribbon of sealant to the top of each glass block, vertically along the center.

• 22

  Remove the tape from the sides of the aquarium. Remove tape residue with a razor blade, if necessary.

• 23

  Place the narrow end rims of the upside down portion of the aquarium on top of the glass blocks, along the ribbons of sealant. Smooth the sealant with your finger, removing excess sealant as needed. Let dry for two days.

Filling Your Aquarium

• 24

  Fill the 20-gallon aquarium until about two inches of space remains under the lip of the upside down portion of the aquarium. Place the Styrofoam ball under the upside down opening.

• 25

  Continue filling the aquarium until the edges of the upside down portion of the aquarium are submerged. There will be little to no water in the air-filled interior of the upside down aquarium.

• 26

  Remove the air from the inside of the upside down tank. Suck on the air tubing until the water rises inside it. Gradually add water to the 20-gallon tank, keeping the edges of the upside down aquarium submerged as it fills. Continue this process until the upside down tank is filled completely. Fill the 20-gallon tank to the top.

• 27

  Remove the tubing and Styrofoam from the tank. Do not dislodge the Styrofoam from the air tubing or it will be trapped under the upside down tank.