DIY Stand Issue

[OceanSprayCranberry]

Built a stand for a 72” 125 gallon using 2x6s and 2x4s with 3/4” plywood top and bottom. The stand was level and the surface was flat when I built it in the garage but after I set the tank on it and put ~25 or so gallons of water in I noticed the plywood kind of warped downwards. The tank is supported on all four corners but the two ends have a substantial gap. Will the plywood flatten out with more weight on it or what should I do?

 

[Islandvib3s]

Built a stand for a 72” 125 gallon using 2x6s and 2x4s with 3/4” plywood top and bottom. The stand was level and the surface was flat when I built it in the garage but after I set the tank on it and put ~25 or so gallons of water in I noticed the plywood kind of warped downwards. The tank is supported on all four corners but the two ends have a substantial gap. Will the plywood flatten out with more weight on it or what should I do?

Did you put cross members? The plywood should stop if the cross members are there. Was it still wet or damp when assembled? Goodluck either way.

 

[Lost in the Sauce]

In that picture can you show where it's sagging and where the gaps are?!

 

[gbroadbridge]

Built a stand for a 72” 125 gallon using 2x6s and 2x4s with 3/4” plywood top and bottom. The stand was level and the surface was flat when I built it in the garage but after I set the tank on it and put ~25 or so gallons of water in I noticed the plywood kind of warped downwards. The tank is supported on all four corners but the two ends have a substantial gap. Will the plywood flatten out with more weight on it or what should I do?

Do you have a photo of just the frame?

 

[welsher7]

On that tank, standard glass tank with full bracing, you only need to support the four corners. As long as you have that covered and the tank is level you shouldn't have any problems. A lot of mass produced stands for rimmed glass tanks only support the corners. That being said i always make sure there is support across the front and back of the tank as well.

 

[OceanSprayCranberry]

Do you have a photo of just the frame?

There are 6 cross members on the top that you can’t see

 

[OceanSprayCranberry]

Did you put cross members? The plywood should stop if the cross members are there. Was it still wet or damp when assembled? Goodluck either way.

Yes 6 total cross members and it was dry when assembled.

In that picture can you show where it's sagging and where the gaps are?!

In the pictures of the two ends if you zoom in you can see light passing through at the bottom of the frame.

 

[Lost in the Sauce]

The corners are supported. When the whole tank is full, you may have full contact. Regardless, I'm not seeing Any issue there. If you wanted to disperse the weight better, you could put a closed cell foam strip like cuts from a yoga mat under the lower frame on the wood.

 

[gbroadbridge]

There are 6 cross members on the top that you can’t see

I'd simply place some firm compressible foam mat between the tank and frame to cover any abnormalities. 1/4 inch thick black so it's not ovious. It'll compress and fill any slight gap.