300 tank build

the entire back wall is the overflow

 

Uuhhhmmm... ok, you still don't understand.
Yes, the "walls" can go whatever way you'd like. Your uprights are fine.
It's the way the horizontal 2x4s around the top of the frame are laid flat, rather than upright. You could refer to the way Reefsparky framed his tank stand in his 90 gallon build thread.

4" flat x 2" high = weak
4" high x 2" flat = strong

I'm not saying you did it wrong, as it should be adequate. I'm just saying you could have built it much stronger using much less wood.

The bottom of your tank acrylic also, correct?
I'm assuming you will have a sheet of plywood over the top side of the stand to support the bottom of the tank as well?

 

I agree with bogie on this one. If you would have put the to two layers of 2x4s vertical instead of horizontal, the stand would be much much stronger. The problem I see though is not about the edges, with vertical support beams every 2 ft the flat 2x4s will still hold. BUT... The center is going to bow downwards, with only two 2x4s going the full length and stretched out over 4 ft laying flat is not strong enough. I bet a 200 lb man can jump up and down on those 2x4's and it be like a springboard bouncing, will it break? No, but will it bow a lot? Yes I would bet at least 1-2 inches in one year, possibly A LOT more... You need some vertical 2x4's or 2x6's to hold the center up, by vertical I do not mean a vertical support beam in the middle of the tank. I mean the long side (the 4 or 6 inch side) is positioned up and down, and the short side (the 2i nch) is side to side thickness.

I really wouldn't want to see you spend all the time building this and spending tons of money just to see a leak on the bottom panel seam, whether that be the first week of setup, a year down the road, or even 5 yrs.

I like watching this and hopefully I don't come off as "you failed" but more "I am trying to help."

 

doubled up its a difference of 1/2", thats not where the strength comes from

two vertical 2x4's could support this tank as long as they dont bend or move side to side.

yes on both

no on both

nope

thanks for the input, the support or strength comes from the vertical supports, joint clearance and gussets. the weakness comes from the bending and hinging. if a board bends or the joints hinge it will break. keep in mind, im the one that has to get under this tank after its filled, not you.

 

Nice work so far guru. Keep up posted on the progress.

 

It would make a tremendous amount of structural difference if you'd replace the single 2x4 (I painted black), with 2-2x4's, instead laid vertically, (longer dimension up and down) side by side. You would have to take a sawsall or similar, to the horizontal (I painted red) 2x4 and cut away the red portion to accomodate this. That would pose no threat to the design, as that single horizontal 2x4 isn't critical for torsion prevention.

The reasoning behind this is since you're not placing a stanchion dead center in the stand (would kinda defeat the purpose of all that open space), this would afford you the next best thing. As james37128 said and I agree; the middle most spot in that stand is going to want to bow over time.

Otherwise, great build!

 

sparky:

here some close ups of the joints to try and explain why it is the way it is, you can get rid of that pic they have been updated.

the cross in the center is there to support the outer walls and give some support for the 3/4" plywood going on top of it for the tank. the bottom of the tank is 3/4" acrylic that will lay flat on the plywood. glass tanks sit on the plastic trim work that wraps around the tank and the glass doesnt touch the stand. ive jumped up and down at the center of the cross and went stand surfing with a side to side motion and the stand didnt move.

the center cross may bend, but not in my life time.

 

looks good, keep it up

 

300 gallons (tank, sand and rocks not included) = 2,400 + lbs
"Surfing" Cop = maybe 200 - 250? lbs

So yeah, that's a valid test approach :.

 

I just read through- my question is: Where is the final location going to be (for the tank)? I'm curious because: what if you have to paint, redo flooring, etc- how do you work around that? (My tank is in the basement on concrete, but we just had to redo wiring in the wall behind it, and although there is about 6-8" clearance, a lot of cursing was involved!)