The big one

[Thefatman]

I am building a big fish tank out of plywood this is a big DIY project it is 4 by 8 by 2 1/2 tank what do u all think about a plywood tank

[cmaxwell39]

Sounds like a cool project. I watched a plywood build on another site a few years ago, and it was definitely fun to watch it come together.

Are you going to put a glass veiwing panel in, or is it going to be a top down view only?

I will be watching.

[Thefatman]

It will be both

[Thefatman]

my new tank

[CUNAReefer]

Very nice, James! This is going to be a massive build!

[Thefatman]

Thinks I love to do new thing and now that I have a house I want to tray to Make a saltwater tank bigger then my 180 so this one will be about 700 I just hope it will work and if u all wold like more pics of what I do to this tank let me know and I will post more pic thinks

[muttley000]

Looking forward to this! Are you going to be fiberglassing the tank?

[cmaxwell39]

Very cool. What size opening do you have for your glass there? Looks like a very large opening unless you plan on making it smaller as you go.

Can't wait to watch this one come together. Keep the pictues coming.

[Thefatman]

I will be going with rubber lining

[Thefatman]

I wold like to keep a big viewing window but we will see when that time comes

[St99iff]

I'm excited to watch this. What thickness plywood are you using? Did you find/use any kind of reference to tell you how and where to brace to withstand the pressure?

[Thefatman]

I'm happy to hear you're excited to answer your first question the bottom is 1 and a half inches thick plywood the side would be 1 inch thick with a 2 by 6 frame and 2 by 4 sides and I will be painting a liquid rubber waterproof rubber

[russeko8]

I have built two of these before and still have the plexiglass from both around. A couple things I would advise through experience one DO NOT put drains through the bottom the plywood expands and contracts with humidity / weather and bulkheads will leak eventually and it becomes a huge problem. Also make sure you have a lot of supports on the bottom I used a steel stand on my 750 with 4 2X8 's through the middle and they still flexed. Also you will need top support to keep it form bowing. on my tank I used threaded rod inside of 1/2" PVC sealed with silicone three across the center. If you would like any more info let me know. Hope this helps big tanks are cool.

Russ

[Thefatman]

thanks man what you say helps a lot I am building the tank slowly and hopefully correctly I have taken my time and read a lot of internet information I would love to see pictures of your too big tanks for the support on the top I will definitely use your idea and when I repost more things I do to my tank I will give you the credit of the support for the top of my tank

[cbonito]

Originally Posted by Thefatman

I will be going with rubber lining

Yeah, I saw some stuff a few people have used called liquid rubber.
They also used a fabric at all the seams that they sealed in with the liquid rubber as well.