320 Gallon Plywood Tank

[3D Reefin']

Hello R2R,

Been thinking about constructing a plywood tank and after checking out @AlexG 's build thread I think I'm ready to start the project. The size is going to be 96"Lx30"Wx26"H, may change by a few inches.

I'm still in the research part of the build, but I plan to make it with the following features.

Side and bottom panels: 1.5" thick (2 - .75" plywood glue and screwed together)
*Glass: 1/2"x 93"L x 25.5 H" annealed low iron
*Stainless steel top brace
*Pond Armor to seal the plywood.
*Steel base with plywood side panels.
*Sump

I do have a few questions regarding how to seal the glass and maintain it in place, but I'll do some more research before I ask.

Here are some early models of the tank, please feel free to make any suggestions or point out things to look out for in plywood aquariums.

This is a cutaway view of the way I plan to install the glass.

 

[AlexG]

I like the design with the two viewing panels and the stainless steel frame. I would recommend RTV108 to seal the glass. Once the glass is in place with spacers it can be braced with some wood to hold it snug. One of my first videos was about installing the glass on my 480 gallon reef. I will say this about RTV108 once its set it is not easy to remove. As I have been tearing my tanks down for a move I was not able to remove the seal with a method I thought would work so I cut the glass off with the wood around its seals.

 

[3D Reefin']

I like the design with the two viewing panels and the stainless steel frame. I would recommend RTV108 to seal the glass. Once the glass is in place with spacers it can be braced with some wood to hold it snug. One of my first videos was about installing the glass on my 480 gallon reef. I will say this about RTV108 once its set it is not easy to remove. As I have been tearing my tanks down for a move I was not able to remove the seal with a method I thought would work so I cut the glass off with the wood around its seals.

Thanks for the silicone recommendation. Its a bummer that you had to take your tanks down, it was a great build.

What are your thoughts on the glass thickness I plan on using?

I have come across a lot of contradicting info regarding glass thickness, and its causing me to second guess myself. I am pretty confident that 1/2" annealed glass should be sufficient for my application, since that is a common thickness used in similar height aquariums. As you can see in the model, its going to be feature a top brace, since I plan on using lids too keep my fish from jumping out. The stainless brace will have at least one cross brace in the middle.

Another thing that I am second guessing is the width of the sealing face, where the glass meets the wood, currently I have it at 1", although I see several people do 1.5"-2.5" but that seams over kill to me. What is the width of the sealing face on your plywood tank?

Thanks for the help

 

[Devaji]

I am dreaming and thinking about a large plywood tank myself.
I was also gonna suggest the RTV108 for the silicone. I here it's great stuff.

I was thinking a side view for my tank too. but I like how you did yours. if I understand it right you are using the 45 alu. to brance that side? or will there be wooden support as well?

 

[Smarkow]

If you are going to put a steel brace along the top, why not consider some steel bracing for the bottom rim as well? Would seem straight forward since you are already planning a steel stand

Love your design! Following

 

[AlexG]

Thanks for the silicone recommendation. Its a bummer that you had to take your tanks down, it was a great build.

What are your thoughts on the glass thickness I plan on using?

I have come across a lot of contradicting info regarding glass thickness, and its causing me to second guess myself. I am pretty confident that 1/2" annealed glass should be sufficient for my application, since that is a common thickness used in similar height aquariums. As you can see in the model, its going to be feature a top brace, since I plan on using lids too keep my fish from jumping out. The stainless brace will have at least one cross brace in the middle.

Another thing that I am second guessing is the width of the sealing face, where the glass meets the wood, currently I have it at 1", although I see several people do 1.5"-2.5" but that seams over kill to me. What is the width of the sealing face on your plywood tank?

Thanks for the help

For glass thickness I would look at the thicknesses that well known and reliable glass tank builders are using as a guide for glass thickness. The overlap I think is a more challenging topic as you want to ensure its enough to account for water pressure and the slight deflection that will occur once the tank is filled.

 

[3D Reefin']

If you are going to put a steel brace along the top, why not consider some steel bracing for the bottom rim as well? Would seem straight forward since you are already planning a steel stand

Love your design! Following

It would be easy to mount it to the top and make it look seamless, would not be as easy to add the stainless brace to the bottom. Plus I don't want to play around with using Pond Armor to transition from wood to stainless steel, not the most friendly material to paint. I did give that some thought, the tank is still in the early stages of design, so things may change a bit, I may figure out a way to do use the stainless all around.

 

[3D Reefin']

For glass thickness I would look at the thicknesses that well known and reliable glass tank builders are using as a guide for glass thickness. The overlap I think is a more challenging topic as you want to ensure its enough to account for water pressure and the slight deflection that will occur once the tank is filled.

By the overlap, you mean the the 90deg joint between the long and short glass or where the glass side panels seal on the edge?

 

[3D Reefin']

I am dreaming and thinking about a large plywood tank myself.
I was also gonna suggest the RTV108 for the silicone. I here it's great stuff.

I was thinking a side view for my tank too. but I like how you did yours. if I understand it right you are using the 45 alu. to brance that side? or will there be wooden support as well?

No aluminium will be used, all 304 or 316 stainless for the top brace. I don't understand what you mean by bracing the side? sorry

 

[Dcal]

Awesome build good luck

 

[Devaji]

No aluminium will be used, all 304 or 316 stainless for the top brace. I don't understand what you mean by bracing the side? sorry

I was thinking for the support between the long and short panels of glass meet up or is the just going to be silicone and your top and bottom bracing system?

 

[3D Reefin']

I was thinking for the support between the long and short panels of glass meet up or is the just going to be silicone and your top and bottom bracing system?

I think I'm going to use silicone to join the two glass panels and the top and bottom braces will provide the support.

 

[Devaji]

I think I'm going to use silicone to join the two glass panels and the top and bottom braces will provide the support.

nice! I was hoping to you do that so I can learn from ya!

 

[3D Reefin']

@AlexG looks like Custom Aquariums uses 1/2" glass for 24"H and 5/8" glass for 30"H for top braced aquariums. So I guess I'll be using 1/2".

 

[3D Reefin']

This is a detail view of how I plan making the joints on the plywood box:

I am going to try to incorporate a chamfer or a fillet in the corners, to try to reduce the stress in that area.

 

[AlexG]

By the overlap, you mean the the 90deg joint between the long and short glass or where the glass side panels seal on the edge?

I was talking more about the overlap of the glass on the plywood. When you are making the glass on glass seal I would also recommend you just stick with using RTV108 instead of using standard silicone that way you are not mixing products together and will have a much stronger seal.

 

[mattgsa]

This looks like a fun build looking forward to seeing it comes along.

 

[3D Reefin']

Worked on the CAD model a bit more, still got a bit more to go. I may use a 75 gallon tank for a sump to save some time, although I'm not sure if I can drill into the side panels, Aqueon lists the 75 gallon as featuring a tempered bottom, but not to sure if they made the sides tempered too. I've come across some threads that show people drilling the side panels successfully and others finding out its tempered. Anyone here drill one for their sump?

Return pumps and skimmer will be placed outside the sump. Base doors will be able to swing open 180deg and feature quick release hinges. Still going back and forth about how I want to mount the lights.

I'm planning on getting the steel and wood next week.

Here are some more views:

 

[maroun.c]

Loving the sketches
Never really researched plywood tanks, nor have good technical knowledge about building them but I had imagined they work great for having a single panel inserted in a joint where water pushes glass towards the wood and glue works as a sealant VS holding glass together. I see in in ur case u have a side glass panel as well and wonder if it'll be structurally as strong as a single pannel tank or a full glass tank where glass attaches to itself on all sides and becomes a single unit. Would the pressure be too much on the front/side glass joint ?

 

[3D Reefin']

Loving the sketches
Never really researched plywood tanks, nor have good technical knowledge about building them but I had imagined they work great for having a single panel inserted in a joint where water pushes glass towards the wood and glue works as a sealant VS holding glass together. I see in in ur case u have a side glass panel as well and wonder if it'll be structurally as strong as a single pannel tank or a full glass tank where glass attaches to itself on all sides and becomes a single unit. Would the pressure be too much on the front/side glass joint ?

Thanks

I gave that quite a thought. I think its fine. 3 of the 4 edges on the glass are supported, the average glass tank only has 2 supports (top brace and bottom brace). For the joint where the two glass pieces meet, I plan to use silicone to join them together as one would seal an all glass tank.