Fish tank stand.....3/4" ply strong enough??

[George Farra]

Hi all

I'm about to start making a stand for a 30 gallon fish tank which will weigh in around 300 pounds (water, gravel, decorations, tank itself). All the commercial stands I've seen are veneered particle board. I'm assuming 3/4" plywood would have sufficient strength to make a cabinet style stand? Or should I build in interior structure out of 2x4 and skin it with a nice hardwood plywood??

If plywood is fine to use, I was contemplating using pocket screw joinery to make the cabinet. Considering the weight should I use traditional dado/glue construction for the cabinet?

Thanks

George

[Erik Loza]

3/4" ply is fine and I don't see a problem with the pocket hole contruction. My big tank weighs about 4,000 lbs. and is 3/4" ply (skinned over a frame but still taking some of the weight)...

http://i75.photobucket.com/albums/i315/erikloza/300%20gallon%20build/Tankfilled-1.jpg
http://i75.photobucket.com/albums/i315/erikloza/300%20gallon%20build/DecemberMbu.jpg

I was a manager for Petco for many years and on more than one occasion, had a customer coem in whose "commercially bought" stand had gotten wet and disintegrated, LOL. Why they sell fish tank stands made of particle board is beyond me. Duh, it's an aquarium!

Best of luck with yours,

Erik Loza
Minimax USA

[George Farra]

Thanks Erik. Those are great tanks BTW!

[Erik Loza]

Thanks, George!

Erik Loza
Minimax USA

[Richard Coers]

Not a big fan of pocket hole joinery where some real strength is needed. You just don't have many screw threads into the veneer. The screw is pointed so you loose the first thread, then it only engages the wood for around 5/8". So really you only have 1/2" of full thread in the wood. I would use biscuits or dominoes. Make sure you get the vertical sides under the tank.

[johnny means]

Pocket screws will be fine. Structurally speaking, five plywood panels taped together at the corners would do just fine.

[Erik Loza]

There are two styles of "common" aquarium stands sold in the pet trade. The worst (and most common...) are composed almost entirely of melamine-laminated particle board. Those are basically pieces of Ikea furniture and use the Confirmat screws and cams for assembly. The other, less common style are the "mission-look" stands made of pine. Those use pocket hole screws.

I sold literally hundreds of aquarium stands over the years and never had an structural issue with any of them and I sold some pretty big ones. Up to 125 gallons. The issues I did see were related to water penetrating the particle board stands and deteriorating them. Never had a real wood stand come back. So, I feel like pocket hole construction is safe for the average fish tank stand.

One tip I would offer to anyone building their own stand would be to consider making it 36" in height. This really adds to the viewing experience, IMO. The average aquarium stand in the store will be 24"-30" in height, which means you often need to bend over to view the tank. Just my 2-cents as always,

Erik Loza
Minimax USA

[Jeff Erbele]

Hi all

I'm about to start making a stand for a 30 gallon fish tank which will weigh in around 300 pounds (water, gravel, decorations, tank itself). All the commercial stands I've seen are veneered particle board. I'm assuming 3/4" plywood would have sufficient strength to make a cabinet style stand? Or should I build in interior structure out of 2x4 and skin it with a nice hardwood plywood??

If plywood is fine to use, I was contemplating using pocket screw joinery to make the cabinet. Considering the weight should I use traditional dado/glue construction for the cabinet?

Thanks

George

Erik is spot on.

I have a 125g All Glass Tank. Fresh water weighs 8.37 lbs / gal as I recall. Last time I looked it up and calculated it, my tank weighs about 1,400 lbs full with water only. From there one starts displacing water with substrate, rocks, fish, plants, trees/roots/wood, rocks/slate, plastic; add anything, add it's weight and deduct the weight of the volume of water it displaces.

One can spend a lot of time calculating and did to a point of it doesn't really matter. My concern was if the floor joists would support the tank. The fact is refrigerators apply more weight per square foot, or per joist, than most retail aquariums do.

The short answer is my 125g sits on 3/4 ply, constructed of a folding base, the front with the left and right ends. There is no back; one is not needed, for support or appearance as it near the wall. The front has 3 cabinet doors. The space between them is compartment-ed with 2 vertical 3/4" plywood panels.

The vertical components sit on a base with small blocks glued in place to locate them, and have a top to match.
The top and bottoms are edged with oak boards, 3/4 x 1 1/2" around the base and 3/4" x 2 3/4" around the top shelf, which also positions the tank on the top.

Those vertical pieces of 3/4" plywood, the front with holes for doors, the ends and two pieces in between support the 125g with a tank foot print of 18" x 72" or 1,296 sq in / 1,400 lbs = 0.9257 lbs per sq inch.

Three quarter ply should be more than adequate for a 30 gallon. The concern is movement and preventing it with simple bracing and blocking so it does not scissors sideways / diagonally. Vertically 3/4" is more than adequate.

[George Farra]

Thanks everyone for your help. After doing more research I'm going to go 3/4" ply with a combo of pocket hole and dado joinery.

George

[Kim Gibbens]

Erik-
Is it feeding time for your puffer? I am assuming that is a fresh water puffer.
Very nice set up you have.

Kim

[Erik Loza]

...My concern was if the floor joists would support the tank. The fact is refrigerators apply more weight per square foot, or per joist, than most retail aquariums do....

We actually poured a slab under the house and blocked up the floor joists, to handle the weight of the big tank. A 30G tank is really nothing, LOL.


Erik-
Is it feeding time for your puffer? I am assuming that is a fresh water puffer.
Very nice set up you have.

Kim

Thanks. Yes, he's an Mbu puffer, 26" long. One of the family!...

http://i75.photobucket.com/albums/i315/erikloza/300%20gallon%20build/photo3_zps1c902e14.jpg

Erik Loza
Minimax USA

[Alan Lightstone]

We chose steel tubing and reinforced concrete. I don't think 3/4" ply would have done it for us:


Of course this weighs 6 tons.

That being said, yours will be fine with 3/4" plywood.

Nice puffer, Erik.

[Grant Wilkinson]

that's a beautiful set up, Alan.

[Jeff Erbele]

We chose steel tubing and reinforced concrete. I don't think 3/4" ply would have done it for us:


Of course this weighs 6 tons.

That being said, yours will be fine with 3/4" plywood.

Nice puffer, Erik.

Very nice does not say enough. ...but stealing the thread; you, not me :)
Is that one tank, (room remodeled over time) or two tanks?

[Erik Loza]

Alan: Wowwwwww......

Erik Loza
Minimax USA

[Erik Loza]

Very nice does not say enough. ...but stealing the thread; you, not me :)
Is that one tank, (room remodeled over time) or two tanks?

Same tank, Jeff. Just progression of time.

Thanks,

Erik Loza
Minimax USA

[Jeff Erbele]

Thanks everyone for your help. After doing more research I'm going to go 3/4" ply with a combo of pocket hole and dado joinery.

George

Done right, that will work just fine.

Engineering wise, a corrugated cardboard box (square and level with no imperfections) would support it; until some lateral force acted upon it. If anything, any force caused it to move horizontally in any direction, or if the box got wet, all bets are off.

Think of a house of cards. How thick (or thin) the cards are not the focus but is your question. The cards could be 3" oak planks but wind could topple them.

Vertical forces; compression is not your weak link.
Preventing shear is your concern.
You do that by selecting the correct material for the application, (plywood, not excessively wet frequently will do fine), the correct size, and preventing movement of the vertical panels. Diagonal "X" bracing certainly would work but even small blocks properly fastened in the right places would do. Dado joints are a plus as are screws and water proof glue; water proof given the application and potetial hazard.

A side note. The assumption of the masses is an aquarium stand and area under it and around it will be wet often. The truth is, that is entirely up to you an how you maintain it. My 125g plywood & oak stand has never been wet in 15 years other than a few occasional drips which I wipe up quickly.

[James Baker SD]

Please no more nice pictures, I've got too many expensive hobbies as it is. :-)

[Alan Lightstone]

Very nice does not say enough. ...but stealing the thread; you, not me :)
Is that one tank, (room remodeled over time) or two tanks?
Same tank between two rooms, and yes, apologies for the thread hijack.

Like Erik and Jeff said, keeping it dry and avoiding racking forces are the important things. Bigger is better for tanks - much more stable an ecosystem.

The critical dimension is height. Just keep a tank less than your arm's length, and maintenance is easy. More than that, and it becomes a challenge.

[Jim Neeley]

The critical dimension is height. Just keep a tank less than your arm's length, and maintenance is easy. More than that, and it becomes a challenge.

More than that and you need flippers!! :D

[Mark Patoka]

I made a hex stand for my 40 gal hex using 3/4 oak plywood and it's plenty strong. I think I just used biscuits and glue. Two of the panels are doors so there are only four panels holding it all up and it's very solid. I think you'll be fine.

[Mike Heidrick]

Those tanks are BEAUTIFUL folks. Great job!

[George Farra]

WOW.....those are really nice tanks and way more than I can accomplish right now. Thanks everyone

George