Diy plywood tank 126" long?

Trying to get an idea of the difficulty in doing something this long

I want a 12w x24h x 126"L tank. I'm thinking about doing one out of plywood just have a few questions before I start building this thing.

1.Can I join plywood together? I can use wood filler between the seam and add the waterproofing membrane on top. I'm not sure where I would find a 126" long piece of plywood much less transport.


2. I have a few gallons left over from tiling the floor that is a crack membrane/waterproofing membrane. Its aquadefence sold by lowes would this be ok to use on the plywood as long as I do several coats? Dont want it to be toxic etc.

3. I'm thinking about using acrylic doing a dozen or so 12x24 pieces for the window and just joining them together before silicon them in place. As long as its a good seal would I have any issue beside the look?

4. How would I get water movement in a tank that long? I'm going to try out saltwater vs freshwater since I already have a freshwater aquarium just on a waaaayy smaller scale.

Thank you so much for the help/advice longtime reader and tried searching for everything before posting

muttley000 said:

Don't know about the aqua defense so won't comment on it, but someone would have to prove it was ok to me. I guess that is a comment . Use 2 layers of plywood and offset your seams is the way I would do it.

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2 layers on the bottom thru the whole thing or just the seams?

piranhaman00 said:

126" long but only 12" wide? At least go 24" wide

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The builder on my house made a weird cutout on the wall 12" wide that takes up half the living room and goes to the patio door. This tank will fill that space and barely let the patio door open. If I do 24" i'll have to make the length smaller and the tank will look out of place sticking out.