2x4 Glue lam for tank stand shelf?

[ReefEco]

Hey reefers, I'm planning a frag tank stand that will house three 12"h x 18"d x 72"L frag tanks (~65 gallons each), stacked - with about 16" vertically between the tanks. I want to avoid center supports on the top two tanks if I can help it. I was thinking of making the shelves out of solid dimensional lumber - basically laminating ~14 kiln-dried 2x4's together to make a solid roughly 3.25" thick shelf to span 72". I have a 20" wood planer so I can do the glue up and run it through to make these shelves perfectly flat. So, the question is if these shelves will be strong enough and not deflect. Normally for a 6ft span tank stand with no center vertical support I would use 2x6's with cross braces and top with 3x4 ply like most DIY stands, but I want to save the vertical inches for more space between the tanks, which is why I'm thinking laminating 2x4's and planing it down to ~3.25" as a solid mass would still be strong enough. Any thoughts out there? Laminating 4x4's could also work - though I don't know which will be more stable long term for each shelf in terms of warping/bending - 14 2x4's or about 6 4x4's. I plan to lacquer prime and then epoxy paint each shelf...

Thanks in advance for the help!

Best, Peter

 

[RocketEngineer]

Your talking about a solid slab 72X18X3.25 holding maybe 650 pounds. That’s 54 pounds per 2x4. I don’t think it’s going to do much :)

 

[ReefEco]

Thanks RocketEngineer - so by "not going to do much" you mean not going to move/deflect much? :)

 

[RocketEngineer]

I’m not sure a normal person would notice.