Introduction: Fish Tank Aquaponics Topper


Welcome to my first instructable! I have been wanting to do this for a while and since I finally had the time I decided to tackle the project of creating an aquaponics garden on top of our fish tank! I mean why not? there is already a conditioned and established tank with fish. So I bought some clay pebbles and aquaponics baskets and the rest I had around the house. Then got to work.

I am sure I will be modifying and improving with time! feel free to leave comments or questions about what you think could help and show pictures if you make one! Let me know how I can make the instructable better for you guys as well!



Fish Tank with water pump (ours is a 30 gallon tank)

Clay Pebbles

Aquaponics Baskets

Old plastic storage bin lid

Lumber (I used mostly 1 x 3 lumber but you can use what you have.) ( I also used one long wooden garden stake for the cross beams)

stain or paint of your choice (I used varathane vintage aqua stain)

polyurethane of your choice (I used Rustoleum triple thick poly)

Wood glue


Measuring tape

Mitre saw

Jigsaw (or something to cut the plastic lid)


Power drill

Finishing nail gun or hammer and nails.

Staple gun

Hot Glue Gun and Hot Glue

Step 1: Plan and Measure

First thing to do when starting a project is to make a plan and measure. Above is a picture of my measurements and rough draft of the plan in my head. I took measurements for both inner and outer distances for the width and length of the top of the tank, as well as the distance of the pump from the back of the tank.

  • Width:
    • inner- 11"
    • outer-12"
  • Length
    • inner- 22.5"
    • outer- 24.25"
    • Distance to front inner lip from the pump 9.5"
    • The Pump stuck out from the back of the tank about 2" which was a used to place the basket holes

Step 2: Start Build, Test Fit, and Final Cut List

  1. I started with just the back and side walls to make sure my measurements came out right by placing it on the fish tank.
  2. Once I made sure everything was going to fit right I assembled the rest of the frame.
  3. Cut list
    • front and back: 24 3/16" (1x3)
    • sides: 12 1/8" (1x2)
    • Front inside lip 22 5/8" (1x3)
    • inside rails 22 5/8" (1x1 or garden stakes)

Step 3: Assembly of the Frame and Measuring the Plastic Top Steps

  1. Once cut attach the front and sides using wood glue and nails. I used a brad nail gun to make this faster and easier but use what you have, nails and hammer or screws and a power drill will get the job done.
  2. Attach the back panel with wood glue and fasteners (nails, screws) and you should have a rectangle with the sides flush with the top of the front and the bottom of the back
  3. Attach the front inside lip flush and perpendicular to the bottom of the front panel with glue and fasteners. 22 5/8" (1x3) to create a resting place for the top of the tank and the plastic panel we will cut later. (see pictures)
  4. Attach the two inside rails flush with the bottom of the side panels. (garden stakes for me but could be 1x1) The first rail is 2" from the back panel and there is a 2 3/4 gap in between the two. This leaves about a 4" gap in between the second rail and the front inside lip from step 3. (see pictures)
  5. Get your storage container lid and place it over the top to measure where to cut. I just drew a line on the lid with a sharpie but you could also measure. (I used a clear one so I could see through and I am glad I did. it looks cooler too!
  6. After measuring and drawing my lines for the plastic top to fit inside the rig cut it out. I used my jig saw again use what you have that you can safely cut through plastic with.
  7. This is where you may need to check out your own tank and see where you need to modify the cut outs for your tank pieces! Once you have your plastic insert cut cut out the back panel spots for your air stones, pump, heater and fan cords or any other item you may have attached.
  • note the sides should be attached on the inside of the front and back panel
  • also the sides should be flush with the top of the front but the bottom of the back panel.

Step 4: Stain and Finish Your Project

Choose a stain or paint you want to use. apply it and then seal it with a clear coat that can withstand the water and humidity of a fish tank.

Step 5: Attach the Plastic Top and Cut Holes for Baskets.

At this point I had already checked for fit a few times on my fish tank so I didn't have any surprises at the end.

I attached my plastic top with a staple gun sparingly because I do not want them falling in the tank but then ended up using hot glue. it did a good job sealing the cracks and attaching the plastic better.

Once the top is attached I placed my baskets and cut the holes with my hole saw and power drill for the aquaponics baskets. I put more in the back because I knew they would receive more water from the pump there. My wife thought the hole saw looked fun so she got in on the action too!

*****note: Do not push too hard with the hole saw like I did on my last hole or you may end up with a crack. I'm rolling with it and using it as a hole to feed our fish through :). If you don't mess up like I did, you will want to cut a window or door or allow some way to drop in food or anything you need to put in you tank.

Step 6: Add a Plastic Flashing (Strip) to the Front Inside Panel to Prevent Water Leakage

I thought I was pretty much done at this point and went back to test again and realized the water was beading up on the bottom of the front inside lip which caused water to drip down the front of the tank.

I fixed this by going to the scraps of my plastic container lid and cutting off one straight-ish strip the length of the inside (22 5/8" so you don't have to scroll up) and attached this kind of like a window flashing to catch the water and guide it back down past the bottom of the board.

To attach I used a staple gun and hot glue again.

Step 7: Finishing Touches and Set Up

  1. Turn off the pump and all the doodads and replace your current top with your new aquaponics rig on the top of your tank
  2. Reattach all the doodads and turn them on
  3. fill your baskets with your rinsed and soaked clay pebbles and put them in the holes.
  4. plant and grow!

Note: We do not use a light for our fish but you could easily adjust the plans for one. I may end up attaching some LED grow lights to it some way if they plants do not get enough sunlight through the window.

Indoor Plants Challenge

Participated in the
Indoor Plants Challenge