Plywood under rimless tank?

[Cv111]

Is it okay to put 3/4" plywood under a 40Gal rimless tank? I find most sheets of plywood are at least a bit warped and therefore not flat. I'm just wondering because I have a steel framed imagitarium tank stand I'd like to use to hold my tank.

 

[Aquavaj]

With that stand and a rimless tank I would definitely use a piece of plywood in between. Get high quality plywood, not that cheap stuff used for siding. I would also check with your tank manufacturer if they require a foam leveling mat on top of the plywood too. Most rimless tanks do.

 

[Victor_C3]

you could just use a piece of MDF instead of plywood. Paint it first so water won’t penetrate it in the event of a spill or splash. MDF is much cheaper and perfectly flat. I believe a 4’ x 8’ sheet of 3/4” MDF goes for $16 at my local Home Depot/Lowe’s.

For the most part, those skinny foam mats do nothing to support or distribute the weight of our tanks. Once the weight gets above 100 or so pounds, the foam is completely compressed.

That’s what I did with my tank.

 

[Spieg]

As long as the stand is sturdy enough (you don't want a stand that will flex if the floor sags a little under the weight), it should be okay to put a deck on top between the stand and tank.

 

[BullyBee]

I am doing the same thing tomorrow. I have a metal stand with a rimless 40 g breeder.

birch plywood and a black finish im thinking.

 

[Cv111]

With that stand and a rimless tank I would definitely use a piece of plywood in between. Get high quality plywood, not that cheap stuff used for siding. I would also check with your tank manufacturer if they require a foam leveling mat on top of the plywood too. Most rimless tanks do.

I have a foam mat already. What do you mean by high quality plywood? I'm not actually familiar with like grades of plywood.

 

[Cv111]

you could just use a piece of MDF instead of plywood. Paint it first so water won’t penetrate it in the event of a spill or splash. MDF is much cheaper and perfectly flat. I believe a 4’ x 8’ sheet of 3/4” MDF goes for $16 at my local Home Depot/Lowe’s.

For the most part, those skinny foam mats do nothing to support or distribute the weight of our tanks. Once the weight gets above 100 or so pounds, the foam is completely compressed.

That’s what I did with my tank.

Is MDF going to be strong enough for a 40 gallon? I was under the understanding that it's much weaker?

 

[snowhite]

I have a foam mat already. What do you mean by high quality plywood? I'm not actually familiar with like grades of plywood.

MDF is particle board and the cheapest. Then there's basic plywood (can see multiple layers when looking at side), then there's sanded plywood that looks a bit nicer, then there's actually Maple, Birch, etc plywood that has nicer finishes. They differ in price by like $10 a 4' x 8' sheet at Home Depot/Lowes.
I was just pricing out building two stands for 48 x 24 frag tanks. Just going to be built from higher grade 2x4's and maple or birch plywood and stained light/dark. Functional goal, but still some "look" to it.

 

[Cv111]

MDF is particle board and the cheapest. Then there's basic plywood (can see multiple layers when looking at side), then there's sanded plywood that looks a bit nicer, then there's actually Maple, Birch, etc plywood that has nicer finishes. They differ in price by like $10 a 4' x 8' sheet at Home Depot/Lowes.

Something like this? https://www.homedepot.com/p/18mm-Sa...ual-0-709-in-x-48-in-x-96-in-454559/203414066

Is it actually likely to be straight/flat? With the typical sanded etc. It's usually warped quite a bit.

 

[snowhite]

Something like this?

Is it actually likely to be straight/flat? With the typical sanded etc. It's usually warped quite a bit.

Functional vs furniture grade... just depends on what you want, and what tools you have access to. Personally... "good enough" is more than good enough.

 

[tsouth]

Thats perfectly fine. It's exactly what I used. 3/4", find the straightest one possible, and they can cut it on side for you. While you're there, pick up a 1/2"+ piece of foam - the high density purple/pink stuff - not white. It should not be easy to compress. Please use both!

 

[Victor_C3]

Is MDF going to be strong enough for a 40 gallon? I was under the understanding that it's much weaker?

If you have a metal framed tank stand and you basically are looking for something to go in between your tank and the metal, MDF will be perfectly strong enough.

I wouldn’t use MDF for anything structural, but it is often used in cheap furniture and more than likely used structurally in cheap aquarium stands as well.

If your stand looks something like this:

Then MDF will be perfect for it.

Also, if you’re looking for a glossy white or black finish, it’s really easy to achieve with MDF. If you want any sort of wood grain, go with plywood.

 

[Uncle99]

When using plywood, you need to be careful that it does not get water on it, it’s not sealed, so if it absorbs water it will expand and that can be big trouble.
That’s why the mat can be an important factor, will allow for some minor flex.

It’s ok to use, but put on a water sealer, or better, use the mat.

 

[hyprc]

MDF is particle board and the cheapest. Then there's basic plywood (can see multiple layers when looking at side), then there's sanded plywood that looks a bit nicer, then there's actually Maple, Birch, etc plywood that has nicer finishes. They differ in price by like $10 a 4' x 8' sheet at Home Depot/Lowes.
I was just pricing out building two stands for 48 x 24 frag tanks. Just going to be built from higher grade 2x4's and maple or birch plywood and stained light/dark. Functional goal, but still some "look" to it.

WHOA now. Many grades of MDF out there, the best of which rival plywood when it comes to resilience to wet/dry cycles.... Plywood will always delaminate/bubble/damage. Good MDF just goes back to business.

Show me the baseboards in rainy northwest homes

 

[RobB'z Reef]

for that size of tank have you considered Type I or II pvc or even HDPE? 1/2" would suffice for that size tank, all your structural support is really coming from the stand and those materials are impervious to salt water.

 

[Sleeping Giant]

3/4" treated plywood with anti-fatigue mat on-top, then lay the rimless tank on that...yes it'll compress, but not come in contact with the wood, which my split, splinter or bend the glass a bit...then it'll crack or chip. The mat is more for piece of mind, then it is for leveling purposes. It's something you can't add afterwards

 

[snowhite]

WHOA now.

When I posted it I expected a MDF/Plywood connoisseur to point out the inadequacies in the specifics of my description.

 

[hyprc]

When I posted it I expected a MDF/Plywood connoisseur to point out the inadequacies in the specifics of my description.

I do the same thing . But a connoisseur I am not, just listen to guys a lot smarter/more experienced than I.

 

[ca1ore]

I’ve got a revolutionary thought ..... how about asking the tank manufacturer what they recommend. Most rimless tank manufacturers require full spanned support for the bottom with a foam layer in between. Plywood has very little support through the thin dimension so would likely only be good of there were cross members in the stand. Good quality BC plywood in 3/4” is generally perfectly flat. Hardwood ply even better. Stay away from the plywood sheathing. I would not personally put MDF or particle board anywhere near my tank.

 

[Silver14SS]

I’ve got a revolutionary thought ..... how about asking the tank manufacturer what they recommend. Most rimless tank manufacturers require full spanned support for the bottom with a foam layer in between. Plywood has very little support through the thin dimension so would likely only be good of there were cross members in the stand. Good quality AC plywood in 3/4” is generally perfectly flat. Hardwood ply even better.

Pssh, like the tank builder would know better than all of us! My preference would to be have nothing mdf on my stand if it can be avoided.