Claire Corlett

Fish Food, Fish Tanks, and More
How To Install a Tank Window

How To Install a Tank Window


I’m going to use this 1000 gallon tank for
my fish. The tank is 5 feet tall and I‘m a bit worried that kids may try to climb up
to see the fish and fall in. I bought a couple of windows for it from The Aquaponic Source
and this is how I installed them. I decided to vertically center the window
in the tank. Measuring down from the rim of the tank, I set the top and marked where the
first drill hole should be. The first hole to be drilled should be one of the top-center
holes in the window. Entering the point of no return, I drilled the hole through the
tank’s wall. It was quite unnerving drilling a hole through such an expensive tank! Using
one of the kit’s bolts, I temporarily hung the window to the exterior of the tank. Using the bolt as a pivot point, it makes
it easy to level the window and mark the center hole along the bottom. I then drill out this
second hole. Not included with the window kit, I found
a long bolt. From the inside of the tank, I put the bolt through the original hole in
the top-center of the window and through the tank. This bolt is used to temporarily hold
the window in place and allows me to force the window to roughly match the curvature
of the tank. I also add a bolt through the bottom hole and lightly tighten the nuts on
them. Now that the window is bolted in place, I
can drill additional holes next to the original anchoring bolts. The window will act as its
own template in the event there are any slight variations in the predrilled holes in the
window. After the adjacent bolts are inserted, the washers and nuts can be added and lightly
tightened. I continued to work my way from the center
to the outer edges. The outer edge holes can be drilled at the same time since the window
is now completely pulled against the tank. Now that I know exactly where all the bolts
are located, I can mark where the cuts can be for the window opening. I used my level
since it is 1 inch thick and marked lines along the bolts. At each corner, I draw a
small curve using a scrap piece of 2 inch pipe. The curved corner will help to prevent
a tear in the tank once there is pressure against it. It’s time to remove the window template.
Just remove all the nuts and push the bolts through. Then remove the long anchor bolts. To cut the window opening, I first started
by drilling a hole for the saw blade and used a saber saw with a new sharp blade. If the
blade gets too warm, it will start to drag and melt the plastic instead of cutting it.
It’s best to stop, let the blade cool and replace it if necessary. After the cutting is complete, all the burrs
need to be removed with a file and then sanded smooth. Also, any burrs around the drill holes
should be removed. The surface of the tank should be completely
cleaned before mounting the window. I cleaned it with water, dried it, cleaned it acetone,
and let it dry again. Just check to make sure the plastic doesn’t react with acetone before
using it! I put a bead of silicone on either side of
the bolt holes. The silicon doesn’t bond to the HDPE tank, and will bond poorly with
the Lexan window so it’s not used as an adhesive. Its purpose is to act as a gasket
between the tank and the window to prevent the water from leaking out. As long as the window still has it protective
coating, it doesn’t need to be cleaned. The window is mounted the same way as it was
when I used it as a template by holding it in place with the long anchor bolts. With the long bolts, you can see how easy
it is to pull in the window to match the tank. When the nut is tightened down, the silicon
bead flattens out in both direction and any air that would be trapped between the beads
escapes through the drill holes. Underneath the head of each bolt, I put a
dab of silicone to prevent the water from leaking through each bolt. Any of the silicone that oozed out of the
joint, I just smoothed out. It doesn’t help with the seal but does clean up the area a
bit. On the bolt heads, I spread the silicone around to make sure there was enough silicone
to cover the polycarbonate and bolt head area. I let the silicone cure for about a week and
the tank is ready for water. So far, no leaks! Thanks for watching.

64 comments on “How To Install a Tank Window

  1. It's great to see the progress. That tank is so big you could become the WeekiWachee springs of Connecticut with mermaid shows too or at least give the New England Aquarium some competition. When do you think you'll have the grow beds set up and what kind of fish will you have?

  2. What an amazing amount of work. Excellent build so far and great video. I was wondering how to install my windows too… thanx ! 😀

  3. I felt like a fish just now…I was enjoying this fine video and spilled some water on my keyboard, so I was trying to suck it out with my mouth before it went haywire!

  4. I'm amazed at how well all your videos come out. I imagine it's no small task to record and then edit them all. I know I speak for everyone when I say that your effort is greatly appreciated! Keep at it; I can't wait to see everything in operation.

  5. Just in case anyone decides to do this or anything involving silicone, note that many silicone's will release a toxic cloud in water which could kill your fish. So buying a non toxic kind is important which you can find tubes of usually at pet stores as "Aquarium Silicone" safe for all your fish.

  6. I was literally just asking my wife today about getting a window. What was the thickness of the plastic that was used ?

  7. Thank you so much for this video. I had thought about the problem of children falling into the tank also. This is the perfect solution.

  8. I agree. I use the clear GE Silicone #2 from the hardware store. I've resealed a few fish tanks with it and it has never been a problem.

  9. Oh my! Well I for one am very grateful, I just saw a huge water tank for sale. $500 and am considering getting it. 1500 gallons. Cut in half I think it would be an ok size. I wouldn't attempt it without having seen this video. I want to see the fish!

  10. Yours is by far my favorite channel on this whole crappy rust bucket. Thank you for posting as much as you do.

  11. Not really. I'm actually going to need to cover the entire tank to minimize the algae growth.

  12. algae can clog the system, take nutrients out of the water, and effects the pH. It's also too cold here to grow them without spending a fortune to heat the water. 😉

  13. You're a brave man. I would have put an angled mirror over the tank with a submersible light in the tank for the kids to see the fish. Nice job on showing how you installed your window.

  14. Web….a question for you to ponder.
    First of all very cool videos, thanks for sharing your skills.
    My question is what happens over time from inner pressure on the plastic tank where the bolt holes were drilled in the corners of the window w/o an outside flange type support that the nuts tighten against?
    My thought is the nuts may cause a damaging affect on the tank and cause it to crack over time and pressure.

  15. I don't think there's enough pressure to cause something like that. Worst case, there's only about 2 PSI pushing against the window. The tank wall is 1/2" thick and there are washers under each nut which helps a bit. I try not to think about catastrophic problems like that! 😉

  16. You are an inspiration to the rest of us who seem such amateurs in comparison. Will you be able to give us an overall cost estimate at some point as I would sincerely like to make a version of this – just not sure if I can afford it. Than you again. Also one of the keys is going to be monitoring and controlling all the parameters of the ENTIRE system, could you share that with us to please.

  17. I'm planning on doing a Q&A video about the dome this summer…. I believe I'll be speaking about it this fall at the Aquaponics Conference too. The building (excavation & materials) is about $30K. If you break out JUST the dome with no foundation work, it's about $7K. The aquaponic setup is an additional cost. 😉

  18. This tank was a scrap tank and is 1000 gallons. There's a link in the description of the video on where you can buy tanks. (I get no kickbacks from them…it's just a good place to purchase from!)

  19. I use clear GE Silicone II from any hardware store. I've used it for years on my various fish tanks. You have to either put silicon under the bolt heads on the inside, or use a rubber washer or o-ring.

  20. What if you designed some kind of cycle that you can use to exercise for yourself and used it to make current so you can give the fish some exercise as well?

  21. Excellent video! I tried the same thing on a smaller tank and my lexan cracked when I was snugging down the bolts! I wasn't rough handling it, nor did I crank them down very hard at all. Im not sure what went wrong. I'm hoping that I can just buy another piece of lexan and try to drill new holes into it instead of scraping the whole thing. Any help would be awesome!

  22. These came predrilled when I bought it. I have heard of people running the drill backward through the lexan so that it would melt instead of "cutting" through the lexan. I guess normal drilling can create microfractures in the material. I'm not an expert with this type of material so I'm just speculating. 😉

  23. Thanks for the really fast response! I'll try just that, I have an extra sheet to use so hopefully I can get the holes lined up just right. fingers crossed!

  24. Drilling into the acrylic backwards worked great, but my window is too wide for the acrylic and it's putting too much stress on it when it conforms to the tank and it cracks anyway.. Maybe a heat gun will help mend it to the tank, not sure if I'll try that though.

  25. I guess that shows my ignorance. I was using acrylic from optix I bought at home depot. I guess lexan is polycarbonate? I'm actually using half of a 55 gallon drum and the window spans 16" wide x 5" tall. I can easily go with a smaller window on a new tank or I could buy a piece of real lexan, but I'll have more in the window than the actual tank lol.

  26. The polycarbonate worked amazingly! I had no issues drilling, fitting, or tightening down the window. No leaks either! Thanks a lot!!

  27. Thank you for making this video. I'm thinking of doing something like this but having much larger viewing windows. I'm looking into buying a 1,000 gallon polyethylene water containment tank and adding the viewing windows. Except the only fish going into it will be Me 🙂 I'm planning on making it a Mermaid tank. It'll be cheaper and more lightweight than an acrylic tank and easier to transport for bookings.

  28. Operating the drill in reverse is a great tip, I used this method on my fish tank window with no issues. 

  29. I also used a heat gun to warm the Lexan before I used the drill in reverse, I noticed its a lot easier to chip and crack the Lexan when its cold.

  30. Excellent project and excellent videos! I'm building a aquaponic system and wanted to add a 11" x 14" small glass window to my fish tank. I was wondering how much apart to drill the holes in the lexan.
    Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *