In wall framing -re-do help...

[scherzo]

I had to redo the stand for my inwall tank - 90 gallon over a 75 gallon tank.
(I'm also converting it to a reef tank)

Both tanks are 48.5" wide so supporting the 90 gallon on top would be interesting because I wouldn't be able to put the "legs" of the stand directly under the corners of the 90.


So I'm going to run 2X6s along the length of the front, middle and back of the 90 gallon tank. I'm only concerned about the short edges. Do they really need to be above a support?

Here is a video of my plan. *Note that there will be another tank below it*

There are walls on the left and the right of the tank so I'm not concerned about sheer although I will probably put another 2X6 across the back just to make sure.

Will this hold up the 90 gallon tank?
YouTube - Aquarium Stand 2

[gklaw]

I am always amazed at how much wood is put into a DIY stand. A 3/4" plywood box, properly fitted with a backing (diaphram) can hold quite a bit.

I think the concern structurally is not how much the vertical load is but if it will rock left and right. If the tank start to move laterally, it does not matter how strong the legs are, it will tip and crash.

Make sure there are diagonal braces to create the stable triangles or add a sheet of plywood even as light as 1/4" to provide a diaphragm to give it lateral stability.

A box built from 3/4" plywood with base and half backing will be plenty in holding up a 90 gallon. I have a 105 gallon sitting on 4 piece of 1" mdf for over 10 years with no problem except for som water damage on the top. To do that over again, I will use 3/4" plywood for sure.

[Jonney_boy]

um.. err.. um...err.. yes it will hold... haha..

If that drawing is to scale, you are going to have six 4x4 legs and have the tank supported on 4 2x6 standing on side. Also, the legs will only be few inches away from the edge of the tank.

imho, as long as you are able to screw and glue the top together properly, that is going to be mighty strong. only "problem" is that the 4x4 posts are only attached on the top, they will "wobble". if you look at designs for most work benches they will have some sort of "frame" on the bottom too so the legs will stay vertical. This will make everything MUCH stronger.

[scherzo]

Thanks for all of the tips.

*I am really bad at google sketchup* The diagram is not to scale..

So I didn't bother to draw in the walls. There are two walls on the left and right of the stand. I will be securing the stand to the walls and also adding a few triangles to help with the "wobble" or "sheer".

[gklaw]

You will have no problem then. Four 4x4 will be more than plenty. They do not really need to be right under the corners. You 2"x6" frame will transfer the load to the legs.

[Aquaman]

I would not use 4x4 s at all .You would be better off using a 2x6 and and 2 -2x4's on each leg having the 2x6 attatch to the side and the 2x4's supporting the top . You would have a more solid top if you had 4 pieces of wood vs the 6 you have. And 4 legs not 6 .The way the top sits on top of the legs will be the least sturdy way of building it.
Just my opinion....I tend to make everything a bit on the ummm....industrial strenghth side.
Good luck with the project

[Jonney_boy]

haha... don't we all overbuild our stands every once in a while.. .LOL..

I figure if I can get my truck balanced propely, I can have it sit ontop of my 20 gal stand..... overkill is nice and gives me a piece of mind.. but if you have ever looked at store bought cabinets it will SCARE you... 150gal stand is no more than a couple of 2x4's and 1-2 braces.

your stand.. inho.. will hold up a LOT more than what you are going to put on it. Sleep well my friend