Question about acrylic tank stand support

[ryudo80]

Does an acrylic tank need multiple cross braces on the top frame if it's already being supported by a 3/4 inch plywood? I plan to build a DIY stand for a 72x24x22 acrylic tank using RocketEngineer's plan with a 3/4 inch plywood on top of a 6" top frame. The plan I see online has a center horizontal brace mainly to prevent twisting. Do I need to add 2 more horizontal braces and make them all level with the outer frame to support the plywood top evenly to prevent the acrylic tank bottom from sagging?

 

[Fish Fan]

Rocket Engineer's stand was geared for rimmed glass tanks that only have to be supported by the rim. I would suggest using some support under your 3/4" plywood to fully support your acrylic tank (which I assume is rimless).

@UncommonSense would be a great member to ask for help here

Best of luck!

 

[UncommonSense]

Do I need to add 2 more horizontal braces and make them all level with the outer frame to support the plywood top evenly to prevent the acrylic tank bottom from sagging?

This would probably be wise!

I’ve seen it done with just perimeter support, but that’s usually on <100g acrylic tanks… something 24” wide will definitely want to bow in the bottom-center over time with no plywood support!

 

[ryudo80]

Ok I think that's what I will do. I will add additional cross braces to the top frame. I will use screws and glue them to the perimeter brace for strength. Also perhaps use joist hangers to support these cross braces. I do plan to add a 3/4 inch plywood on top of frame.

 

[UncommonSense]

Ok I think that's what I will do. I will add additional cross braces to the top frame. I will use screws and glue them to the perimeter brace for strength. I do plan to add a 3/4 inch plywood on top of frame.

This works best if the support lands on a vertical framing member… is that possible? — possibly by notching lumber?

 

[ryudo80]

I could add the same horizonal brace on the bottom frame and add additional 2x4's and turn them side way to support both the perimeter frame and the horizontal braces in the middle of the stand. . For the two braces to the left & right of the middle brace, I was hoping to use simpson joist hanger so I have some clearance to access inside the stand without additional vertical braces in the way.

 

[UncommonSense]

I could add the same horizonal brace on the bottom frame and add additional 2x4's and turn them side way to support both the perimeter frame and the horizontal braces in the middle of the stand. . For the two braces to the left & right of the middle brace, I was hoping to use simpson joist hanger so I have some clearance to access inside the stand without additional vertical braces in the way.

Ah! With hangers and dedicated hanger screws, you should be fine!