720 gallon help

[Veen32]

im building a 720 gallon plywood aquarium (6'x3'x3') with one glass viewing panel. My worry is about the stand. I was planning on using some 4x4's and 2x6's to build a stand similar to this. Please let me know your thoughts and opinions.

 

[Veen32]

To be clear I was going to use 4x4's as the 4 uprights shown in the photo, and then use 2x6's screwed to that between the lower and upper part.

 

[Drstrangelove]

That's not 720 gallons.

Personally, I think I would want better cross support to make sure the columns won't move. It appears that you are relying on fasteners at the bottom, and I don't think I'd trust that structure to be stable under that load. The 4x4s won't solve the issue of the top moving laterally under a load.

I haven't built stands, but that's what it looks like to me. I'd look for a more sturdy design.


There are some really good designs I've seen from time to time in this forum, so I'd probably look around for those and see if they look stronger.

 

[EighthNotch]

Good luck finding straight 4x4's at any big box hardware store. Why not build it with only 2x6's and follow designs that are pinned on here?

The stand design you posted looks to me it's good for about a 20 gallon long or a 55 gallon (that stand is kinda pushing it for a 55 IMO). I understand you'll be scaling it up and using different lumber but that won't cut it in my opinion.

720 gallons weighs as much as a full-size pickup truck.

 

[GeorgeInNePa]

As above, I would just use 2x6s and add diagonal braces.

 

[Jez1992]

This is what you want. This tank is 3 ft deep, however 8ft long so you'd have to build shorter.

 

[BIG-G]

I think if you make sure the top frame is supported directly by the 4x4 and not by the fasteners and add plenty of support posts to cover the spam you should be good.
BTW 6x3x3 is right around 400 gallons.

 

[M1A1]

4x4's are the least stable lumber available - they will warp, twist and split even in the best of conditions. The standard 2x4 and 2x6 plans are more than enough for a tank this size, or even for a tank twice this size.

 

[Arthur]

I don't understand why more people don't buy a kreg jig for building tank stands. I built 4 picture frames out of 2x6's and screwed them together for my 270g stand. Couldn't have been easier, and is super solid