New Plywood Stand.

[DIYreefer]

Everything in these pictures is plywood (including one of the tanks) if it isn't glass. These are my frag tanks and my 125 display tank.







Please excuse the mess. You guys caught me on maintenance day.

 

[ShakeyGizzard]

It looks like the bulk of the weight is distributed to the corner 2x4s, the cross beams aren't really doing much. Fortunately, they put some plywood across the top to help distribute the weight more evenly. This is not a design I would use, but I'm sure it works just fine.

the bottom only needs supported on rimless tanks. rimmed tanks need perimeter supported. Also olny used 2x4 since i had plenty on hand from another project.

 

[ShakeyGizzard]

Geeze, Not knocking plywood, built plenty out of it, along with cabinets, kitchen islands, doors, floors, walls, etc. mines only a 40b. tank. the 2x4 cost me nothing, the skins did. But birch plywood is costly. Would not use the cheap plywood. my stand is way overkill support wise for the tank. I also have quite a few stands out there, due to close friendship with an aquarium cleaning service . I build to customers desires. If they want a modern stand that's flush with the aquarium and also wants a large sump, plywood is the material of choice. large aquariums (180 gal. and up) require trust worthy support. also ones knowledge of selecting wood for purchase goes along way to prevent any problems with a build. the big secret is, if it works, it works. On a side note on rimless tanks, I do plane the tops perfectly flat. But still require a mat under the tank.

 

[twentyleagues]

Everything in these pictures is plywood (including one of the tanks) if it isn't glass. These are my frag tanks and my 125 display tank.







Please excuse the mess. You guys caught me on maintenance day.

Thats a mess!? lol You should see my fish room on a normal day let alone water change day.
Looks great! I am working up the "courage" to build a plywood tank. Had all the stuff to do so a few years ago then stuff happened and I didnt. Some of my freshwater stuff needs bigger tanks. May do a larger reef too if the first build works out.

 

[homer1475]

3/4 baltic birch plywood, 80G rimless with 30G sump. Think I made this 4 years ago now? 3 coats of primer, 2 top coats of black enamel. Interior is sealed with painters caulk, 3 coats of primer, 2 coats of white appliance epoxy paint.

Plywood, if built correctly, will hold a tank just fine.

Edit:
Added a couple pics.

 

[Fishess]

Plywood is plenty strong for what you want to do. I would use 3/4" not just for the weight, but if you are screwing the panels together it gives you more "meat" to screw into. You risk blowing out the side with a screw if you use 1/2".

I originally was planning to use 1 3/8" (35mm)plywood.
I figure 1 inch (25mm) should be plenty strong? I may go with 1 13/16 (30mm) to have worry free mind.

IDK why, but 3/4" seems very "thin". Then again i have seen the "store" MDF stands that hold 100G tanks... Go figure.

 

[twentyleagues]

I originally was planning to use 1 3/8" (35mm)plywood.
I figure 1 inch (25mm) should be plenty strong? I may go with 1 13/16 (30mm) to have worry free mind.

IDK why, but 3/4" seems very "thin". Then again i have seen the "store" MDF stands that hold 100G tanks... Go figure.

Like I said my 180 is on a 3/4" walnut ply stand. Its plenty strong. I think what others have said about the quality of the plywood or what kind of plywood it is as important as how its built.

 

[Fishess]

The whole water damage thing is a bit misleading. It would take A LOT of water, and over a significant period of time to do any real damage. People fail to realize/remember that the vast majority of high productions stands are actually made out of veneered MDF. Which is FAR less tolerant of water than plywood is. They use it because it's cost effective and it works. It's not the best choice, IMO, but yeah, even MDF would be sufficient if designed/built correctly.

The reason why I stopped doing 2x4 stands is because you are putting a whole lot of faith into one piece of wood, with one grain pattern. Some one else posted a claim of a 2x4 being good to hold 1,000 lbs and I think that is incorrect (I think what I've seen in the past is 500 lbs, but I digress), but with plywood you get exceedingly enough strength for most applications along with the peace of mind of knowing that if there was any weakness in the wood itself, it would very likely only be in one ply. With a 2x4, it's one 2x4, and if it's bad the whole thing goes boom. I also quit using 2x4's because it creates a stand that is overly bulky and doesn't allow for much room for a sump underneath.

Yeah those MDF "store" stand are sketchy as hell. IDK even 3/4" plywood seems to thin for me.. As i was originally thinking about using 1 3/8" (35mm) plywood.

If 3/4" (18mm) seems strong enough for my build.. I could go 1 inch (25mm) for easy of mind. Or even better 1 13/16 (30mm).. Price wise they all are almost the same. Only difference will be more heavy stand and stronger. Same time i don't want to go overboard by having too heavy stand.. I'm leaning on 1 13/16 (30mm).. Plywood. IDK how safe the 1inch plywood will be.. I wonder how much it could handle weight wise. If it's over 200G i could easily go with 1inch then.

 

[Fishess]

Like I said my 180 is on a 3/4" walnut ply stand. Its plenty strong. I think what others have said about the quality of the plywood or what kind of plywood it is as important as how its built.

Watched the video.
Yup i get that. I want my stand to be simple box. With enforced top (Same as in video) - because aquarium will not be sitting on corners, but in middle of stand. If i go by my "images" will the 3/4" really do the work?
As you said it's important how it's built - which i don't know how good is mine.

I can imagine side walls wanting to "bow" inwards because of aquarium sitting in middle of stand - that's why i added those 4 (red logs) at top. So it should not bend/bow.

 

[twentyleagues]

Yup i get that. I want my stand to be simple box. With enforced top - because aquarium will not be sitting on corners, but in middle of stand. If i go by my "images" will the 3/4" really do the work?
As you said it's important how it's built - which i don't know how good is mine.

I can imagine side walls wanting to "bow" inwards because of aquarium sitting in middle of stand - that's why i added those 4 (red logs) at top. So it should not bend/bow.

Yeah I dont know about that. Id think you'd want the weight to be over the side walls or it would be very "unstable". With your design the weight would pull on the connection points of the top to the sides. Traditionally the weight would be pressing down on the top and sides transferring the weight to the floor. There may be a way to properly build this to perform the task you want, but I dont know how youd do it. I have built many 2x4 stands and racks with no issues. I am not an accomplished wood worker, I dont know how you'd do this or even if you could. You could do it with a 2x4 stand but even that will need support in the correct places.

What is your reasoning for this?

 

[Fishess]

Yeah I dont know about that. Id think you'd want the weight to be over the side walls or it would be very "unstable". With your design the weight would pull on the connection points of the top to the sides. Traditionally the weight would be pressing down on the top and sides transferring the weight to the floor. There may be a way to properly build this to perform the task you want, but I dont know how youd do it. I have built many 2x4 stands and racks with no issues. I am not an accomplished wood worker, I dont know how you'd do this or even if you could. You could do it with a 2x4 stand but even that will need support in the correct places.

What is your reasoning for this?

I have big steel cabinet that i need and sits in my room. I have noticed that i don't use the space under my aquarium.. (Plywood stand with middle brace/leg - having the middle part - i can't put it there.) So i figured i could combine both. (I have very small room..)

Like i said before. I will be putting also very thick countertop 1 5/8" (40mm) (The countertop will be going over the corners of stand. "TT" Box under, island on top.)
Need be i can use angled steel bar and screw that to bottom of the top.. I figured - if top is very strong one big "log" like - it would not bend and all top would act like one big piece. It would be the same as having aquarium on corners. No?
Back would hold everything together. (The back and side walls would be sandwiched between top and bottom.)

 

[twentyleagues]

I have big steel cabinet that i need and sits in my room. I have noticed that i don't use the space under my aquarium.. (Plywood stand with middle brace/leg - having the middle part - i can't put it there.) So i figured i could combine both. (I have very small room..)

Like i said before. I will be putting also very thick countertop 1 5/8" (40mm) (The countertop will be going over the corners of stand. "TT" Box under, island on top.)
Need be i can use angled steel bar and screw that to bottom of the top.. I figured - if top is very strong one big "log" like - it would not bend and all top would act like one big piece. It would be the same as having aquarium on corners. No?
Back would hold everything together. (The back and side walls would be sandwiched between top and bottom.)

I over build all my stands. So, I am not the best one to talk about this. But, I have disassembled a stand that was built by the same guy that built the one for my 180 and honestly I was surprised at how simple the construction actually was. Again though these are built to fit the tank in question. I would guess with the appropriate bracing and top it may work.

 

[DIYreefer]

I originally was planning to use 1 3/8" (35mm)plywood.
I figure 1 inch (25mm) should be plenty strong? I may go with 1 13/16 (30mm) to have worry free mind.

IDK why, but 3/4" seems very "thin". Then again i have seen the "store" MDF stands that hold 100G tanks... Go figure.

I understand the apprehension, 3/4" does seem like it wouldn't work but the truth is that it's more than strong enough for most hobbyist applications.

 

[Fishess]

What if i add square metal tubes going from one wall to other wall. (The tube would sit on the side wall)
3-4mm metal tube or angle bar won't be bending in first place under 55Gallons. And by running 2-4 side by side that weight gets split into 2-4..
And because metal will not bend in first place - it would be the same as having aquarium sitting on corners of the stand?

More or less it would go the same as (RED 2x4 from my images), but over the walls. The weight from middle of stand will be carried by steel tubes onto walls. < Or am i wrong?
Cutting steel angle bar or square tube isn't a problem to me.

 

[Brett7397]

My 55 gal stand is made from 1x's like shelving boards. It came with the tank. I've had this tank for almost 30 years. I have resealed once.

 

[Fishess]

My 55 gal stand is made from 1x's like shelving boards. It came with the tank. I've had this tank for almost 30 years. I have resealed once.

Yeah the shelving's helps holding the stand together. I myself have shelving type plywood stand right now.. It doesn't move even if i would try to force it over/bend sideways.

That rigidness gets lost, if you have empty/hollow middle.

 

[Joekovar]

3/4" cabinet grade birch plywood.

Use the leftover from the sheet used to get the top/bottom, for the ledger in the last image, and doubling up the joists.

Glue everything. Joints, where the header doubles up, the doubled up joists. the ledger to the side.

 

[Fishess]

3/4" cabinet grade birch plywood.

Use the leftover from the sheet used to get the top/bottom, for the ledger in the last image, and doubling up the joists.

Glue everything. Joints, where the header doubles up, the doubled up joists. the ledger to the side.

It's the same stand i had in first post. Only at front added strips at both walls? An under the top are extra support brackets that holds the strips that hold top.

Can't i use angled steel bar at front? (Frame like) That would be screwed in the plywood? Or are plywood+screws+glue stronger?

Are the front strips actually needed? My guess - it's to prevent the stand walls wanting to explode/implode on itself? right? If i'm using 1" plywood doesn't the need of front strips go away?

And if it's for prevent the walls from exploding/imploding under aquarium weight. Can't i simply screw some angled steel bar at the side wall edge? (Around front opening like a frame) Or even better use "U" shape steel profile put on the plywood edge? < I could put a car on the stand then...

 

[Joekovar]

My side panels have notches cut out of the front for the header to sit in. This lets the side panels, vs sheer strength of fasteners bear most of the weight across the header. It also provides more surface for glue between that joint.

Given your tank will sit in the middle of the top, you want to distribute that weight to the sides and back in multiple places. I'd layout my joists starting with doubled up plywood rips directly under the front and back edges of the tank, and add another single rip or two in-between.

If you screw through the side panels into 2x4s like in your first image, a lot of your lateral load strength (resistance to the wavemakers sloshing the water side to side, and drunk girls leaning against it) will fall on the pull out strength of your fasteners going parallel to the grain of the 2x4. The same holds true for screwing a steel header into the sides. Though screwing a plate welded to the steel header and screwing that to the inside of the sides would be significantly stronger than going into a 2x4 parallel to the wood grain.

The front uprights stiffen the sides. Again, I'm thinking about lateral load here. Them also serving as ledge area to bear some of the headers weight happened inadvertently.

Plywood boxes can be extremely strong. Attention must be paid to resisting forces that act on it from the sides, rather than just dead weight sitting on top though.

 

[Fishess]

My side panels have notches cut out of the front for the header to sit in. This lets the side panels, vs sheer strength of fasteners bear most of the weight across the header. It also provides more surface for glue between that joint.

Given your tank will sit in the middle of the top, you want to distribute that weight to the sides and back in multiple places. I'd layout my joists starting with doubled up plywood rips directly under the front and back edges of the tank, and add another single rip or two in-between.

If you screw through the side panels into 2x4s like in your first image, a lot of your lateral load strength (resistance to the wavemakers sloshing the water side to side, and drunk girls leaning against it) will fall on the pull out strength of your fasteners going parallel to the grain of the 2x4. The same holds true for screwing a steel header into the sides. Though screwing a plate welded to the steel header and screwing that to the inside of the sides would be significantly stronger than going into a 2x4 parallel to the wood grain.

The front uprights stiffen the sides. Again, I'm thinking about lateral load here. Them also serving as ledge area to bear some of the headers weight happened inadvertently.

Plywood boxes can be extremely strong. Attention must be paid to resisting forces that act on it from the sides, rather than just dead weight sitting on top though.

I see. The top is already sitting on back wall. I was already planning adding the strips under top anyways. No problem adding another strip under those going sideways (like in your image)

But at front isn't it better to have "L" corner going all around the box outer edge? It would hold side walls and top in one place, allowing it to have stronger lateral load. I mean literal frame - angled steel bar (bent) all around the front. And by screws - i mean literally drilling holes true plywood and have big bolt with washer sandwiching the plywood and frame. 10-13 bolts per wall/top.

I simply thought by having metal frame going around the front - would result in very strong stand. It would act like backwall..
I'm talking about 3-4mm steel frame here.