My 3665 Gallon Lined Plywood Tank Build Log

[Nolapete]

Here's a colorful diagram. I'll try to explain the process.

First mark the dimensions of the bottom of your tank on to your liner.

The red folds are first.

Fold along the front and back edges toward the inside of the tank.

Fold along the side edges toward the inside of the tank.

The trick is to have the triangle of liner on each corner on the outside instead of the inside.

Fold the right back triangle (yellow) toward the left back corner.

Fold the left back triangle (green) toward the right back corner.

Fold the front triangles (blue) toward the back and wrap around if needed.

No seams, no folds inside the tank, and the front has no overlapping folds so the viewing window is just covered by 1 layer making it very clean fit.

 

[Nolapete]

Here's the front.

 

[jmhart]

This could be epic

 

[Weezer]

This could be epic

opcorn:

 

[Nolapete]

I cut down my paper model to the height that it should be and the side triangle don't overlap to the back and the the back triangles don't overlap each other as in the diagrams I last posted. I flattened out the paper so that I could get the dimensions of the liner needed. I'll need a 20'x25' liner with 12" overlap in front and back and 18" overlap on the sides. Plenty room since the walls are 2x6 lumber.

I took a break and didn't start emptying the fish room tonight because it's supposed to be cold tomorrow. I started painting my foyer instead. Olympic Paints Serene Sea (Blue) B53-3. It looks fantastic.

 

[Luc]

You're not paid to take a break.....

 

[Luc]

Joking...but, a classic example of outside the box thinking.
Seamless folding all of it inside is indeed some very interesting idea.
I might be asking the obvious, shoot me for it, but that means you're going to drape only 1 layer inside the walls of your tank and everything else will be draped over and outside your tank?
That will nicely protect your wood against splashing water as well.

 

[Bubbles2112]

opcorn:

I love it when a plan comes together!

 

[Nolapete]

No, the entire liner will be inside the tank with 12-18" overlapping the top of the tank wall. The folds are between the liner and the plywood. Normally, people have the excess "folds" inside the pond or, like my friend in his 2600 gallon tanks, inside the tank.

Take a sheet of paper and try to follow my instructions on folding the liner. Make the bottom of your pond 12 x 8 (you can use inches or centimeters, it doesn't matter) I actually used the width of the lines on the paper I was using as a scale.

There's going to be an 18" plexiglass splash guard around the entire tank which will also help to keep fish from jumping out.

 

[Nolapete]

It's funny how the longer you work with something the more solutions are revealed. I was attempting to recreate my paper scale model freehand this morning to see if the method worked for any rectangular/square tank. I accidently folded one of the back folds to the side instead of to the back. This made it where the front and back walls of the tank don't have any folds behind them. All the four corners fold to the sides making the front and back walls flush against the plywood. Bulkhead fittings are going to be a breeze to install now.

I know this is hard to visualize, so I'll take some pictures of my fold model tonight.