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.