Need help with stand plans

[SallyWho]

I'm planning on building the stand for my first reef tank myself. I'm not a vastly experienced carpenter, but I can handle a drill and am learning to handle a circular saw. I built a sturdy but plain stand for my 30g freshwater planted tank a while back (with a little help figuring out the door), so it won't be my first stand build, though it'll definitely be more challenging! The tank will be a 4x2x2 120 gallon. The stand will be 6' long, 30" front to back, and 36" tall (yes, I know I'll need a stepladder for maintenance). I want the stand to be built larger than the tank because I'd like to maximize the space underneath for equipment, and having some extra room around the edges to stand on for maintenance or to place things on would be nice. Basically, I took that pretty common color-coded base stand design from Google and tweaked it. I tried to mock up some drawings, but I'm no artist and these definitely aren't to scale. My concern is that the weight of the tank isn't directly resting on the four corners of the stand. That's why I have another 2x4 placed parallel to the front horizontal frame board to support the front of the tank. Likewise, I've added perpendicular joists to support the sides of the tank, so it isn't just floating. There will be one front center brace, and at least one (maybe two) braces in the back. All four stand corners will have support inside and out, and top to bottom. What are your thoughts? Is this a house of cards? Am I missing anything terribly important? I hope to be able to use 2x4s for the whole thing. What are your thoughts on that? Or should I go with 2x6s for the top and bottom frames? I've got a little time to tweak this design because I haven't even bought the lumber yet, but I'll be buying lumber soon for another project...so I figured I'd buy all the lumber at once so I only have to borrow a truck once. Check out the PDF with my scanned plans and let me know what you think! Thanks!

 

[Ryan115]

I would definitely recommend at least 2x6's for the top frame. My 6' 180g used 2x8's with no center brace (so same length, but less weight) and my 4' 90g will be using 2x6s. No need for them on the bottom, as it isn't really supporting the weight, just transferring it to the floor.
My main concern with the design is that the center long horizontal board is unsupported on the ends. You would be relying on a (rather weak) butt-joint. If you were to add supports under each end then you would basically have a 24" wide stand with an extra 6" added to the front, if that makes sense.
Are you planning to add any knee braces or plywood skin to eliminate racking? I'm looking at that right now to see what is actually necessary.

 

[SallyWho]

Knee braces? I feel a little ignorant....I am going to have horizontal braces on the sides at about middle height, if that's what you mean. Those are shown in the bottom doodle labeled "side" on the attachment in the original post.

When you mentioned the center long, horizontal board, are you talking about the board that corresponds to the red plank in that color-coded thing that I modified? If so, it will be supported on both ends by boards represented by magenta and green on the diagram (though I'm bringing my "green" boards all the way flush to the top). If you were talking about something else, could you clarify? Thanks!

 

[prsnlty]

The cross beam that will actually be supporting the tank needs to be supported at each end also. Since you're not going to be using the sides for Access I would add another floor to beam support on each end. Just like a corner but without the corner. And yes I would be concerned about racking. What we did when ours racked is we squared it off this way as shown in the picture.

 

[prsnlty]

The point is that if you don't put the support under the main crossbeam at each end then it will not carry the weight to the floor it will carry it to the frame at the top. And yes for the top I would use 2X6.

 

[prsnlty]

We overbuilt ours in one end since it's a peninsula and we wanted a slide out drawer at the wall end but the entire frame of the tank is completely supported anything outside of that frame doesn't need to be unless like you said your going to be standing on it. And every length that carries the tank weight must have a support beam to the floor at the end of it. So just like you build your corners you're going to do the same underneath at each end in order to carry that weight down.

Ignore the 1st pc boards on the flat, after this pic it had them upright for flooring & waterproofing.

We overbuilt this frame so we could have a 4-inch ledge all the way around as well as the slide out.

 

[SallyWho]

The cross beam that will actually be supporting the tank needs to be supported at each end also. Since you're not going to be using the sides for Access I would add another floor to beam support on each end. Just like a corner but without the corner. And yes I would be concerned about racking. What we did when ours racked is we squared it off this way as shown in the picture.

Oh, you mean a support to the floor for each joist that the tank rests on since the tank doesn't actually rest on any of the stand's four corners?

 

[prsnlty]

Oh, you mean a support to the floor for each joist that the tank rests on since the tank doesn't actually rest on any of the stand's four corners?

Yes [emoji6]

 

[SallyWho]

Gaaaaaahtcha! Sorry, I'm not always real quick on the uptake! I'll twiddle with it and see if I can find a way to support those joists without dropping legs through the middle of my sump....

 

[prsnlty]

Gaaaaaahtcha! Sorry, I'm not always real quick on the uptake! [emoji14] I'll twiddle with it and see if I can find a way to support those joists without dropping legs through the middle of my sump....

They only need to be on the ends.

 

[SallyWho]

So in this from-the-top-down view, I'd just need to add support to the circled spots? Those three joists are what the actual tank will be resting on. Simple as making those supports act like multiple vertical center braces in the back?

 

[prsnlty]

Where I circled

 

[prsnlty]

Plus your four outside corners that you already have shown

 

[SallyWho]

Hahaha! Thanks so much for your patience! I really appreciate your advice.

 

[prsnlty]

Hahaha! Thanks so much for your patience! I really appreciate your advice.

You're welcome, that's what we're here for [emoji12]
And welcome to Reef 2 Reef!

 

[cj in sac ca]

Will be heavy but you. An use 4x4 on the corners. Then use 2x6s for top and sides rails. Few years back I had a 120 that the stand was a homemade one built this way. Was extremely heavy but stable. I'm 6'3"and at the time was 250lbs and it held the tank "glass one", the 120plus lbs of rock water corals fish and me standing on the lip of the stand with no issues. Good luck and post pics when it's done.

 

[Ryan115]

The two braces on each end were the main ones that I was concerned about.
Also here is a picture that explains the knee braces for the stand.
Not as bad as they show here, because the green boards that you have end up helping out, but these are much stronger.

 

[Ryan115]

Also, that picture has them attached to the outside, I put them in-line like prsnlty did.