2mm gap between 180 gallon tank and stand

  • We are currently upgrading MFK. thanks! -neo

Eric99

Gambusia
MFK Member
Mar 27, 2008
317
0
16
Pittsburgh, Pa
I made my own stand but myself and a few friends put the tank on the stand and it looks like the 2 by 4's may have a slight bow in them in the middle. The corners touch down solid. My question is will the tank be ok like this? It would be a major headache if I had to tear my middle braces out and redo them.
 
It would be even more of a headache cleaning up a 180gallons of water.

Had to give advise, you desciption of the stand is vague. Is your tank made so that the glass sits on the stand or does it have plastic framing that holds the glass up of the stand?
 
This is going to go against what a lot of people think/say about stands: The front and back panels act as I-beams and can safely support the tank and bottom as long as the four corners are evenly supported. Still knowing this, I am not comfortable with doing it. It is critical that the four corners of the stand be exactly in a plane and provide equal support to the aquarium. If not, the tank will twist/torque and cause excessive stress on the seams. Failure of the seams is commonly attributed to tanks being unevenly supported. If the tank were on a concrete or tile floor so you could shim any imperfections, I'd say you are good to go dispite the problem. However, it appears that the flooring is carpet and already on (shims?). Carpet does not allow you to check the exactness of the subfloor and the compression of the carpet and pad will give you the false sense of security that everything is fine. The stand is not beefy enough to transfer loads from an inadequately supported corner, so it should not be used on carpet.
 
CHOMPERS;2402197; said:
...The stand is not beefy enough to transfer loads from an inadequately supported corner, so it should not be used on carpet.

Since "beefy enough" is very subjective, I think it could use some clarification. What occurs when a corner is not supported, is what is called a 'moment arm'. Basically that is when a force is applied but it is supported somewhere else. Here the force is applied at an unsupported corner and the force is transfered through the horizontal 2x4's to the vertical 4x4's. It creates a twisting force or moment at the supporting end which must be countered by the joint where the 2x4 meets the 4x4. (Overall it is much more complex than that but I am trying to make this simple.) I can't judge the quality of the joints but the math will say NO reguardless. Even if the one across the back were strong enough, the 2x4 could not transfer 25% of the weight without flexing. So that makes a double 'no'.

The best solution of course is to add a center support in the back and replace the one in the front so that the top 2x4's are brought straight. It is also wise to add plywood to the back and two sides (this will strengthen the stand enough so that it can be used on an uneven floor). If the sides and back are skinned, adding trim (decorative molding, base boards, crown molding, etc.) will really dress it up.
 
After looking at the pictures again, I noticed that the center brace was in the back rather than the front. Not that it matters, but it got me thinking that if only the front was warped, it might be easy to just add a center brace to the front to straighten it. A center brace will also remove a lot of the moment issue.
 
I'm gonna contradict you here Chompers... sort of. Everything you said makes sense, but I think we're dramatizing the situation. 2mm, or .05" is not a whole lot of warp for a 2x4, and there are a LOT of 2x4 stands on this forum. I've seen a lot of stands with worse irregularities than that (being off level mostly). What you said about the 4 corners being supported is dead on. In most tanks the bottom is suspended about 1/2" above the actual surface the tank is sitting on, anyway, so supporting the faces of the tank anywhere other than the corners doesn't do much. If the tank cannot be 'rocked' (IE, it's not sitting on 3 corners, with the third elevated) then you should be OK. If you are really concerned about it, I'd go get some closed cell polyurethane foam (the foam insulation will be too stiff to make up .05"), and put that under your tank for a bit of load distribution.
 
Thanks everyone. What you don't realize is that this tank is on very thin carpet on a concrete basement floor. I shimmed it up to fit level and it is very firm-the tank will not rock at all. They told me at the lfs that as long as my corners are supported well it should be ok. As for the center braces, there are two of them but I do not have the front one in yet because I have to get my 75 gallon wet/dry in there first. This stand is probably strong enough to hold 3000 lbs honestly. I just wanted to make sure that my glass wont crack. I am going to fill it up next week and see what happens. Also, the posts are 4 by 4's, the top is 3/4" birch plywood, the boards on top are 2 by 4's, the boards on the bottom and the center braces are 2 by 6's.
 
Just some updates here. I siliconed those fake plants to the bottom so my rays and eels will not uproot them. Also if you notice the overflow boxes were removed and I scrubbed them and put them back in but left the front covers off and cut out rectangular holes near the top for better flow. The bottom pic is of my homemade canopy. It has 2 piano hinges midway so that I can just lift it up when I need to feed the fish or clean the tank. It is heavy though-made out of solid oak.

P-Bass 004.jpg

P-Bass 007.jpg

P-Bass 008.jpg

P-Bass 002.jpg
 
MonsterFishKeepers.com