Hydroponic trough frag tank stand ideas?

[fermentedhiker]

I'm in the planning stages of setting up some propagation troughs. Based on my space I'm leaning towards some hydroponic reservoirs from Botanicare. They are nominally 115 gallons and measure 83x35x12.

Originally I was thinking of building them similar to tidal gardens out of aluminum T-slot. But looking at framingtech's website it looked like(I didn't contact them for an actual quote just basing it on the pre arranged kits they had for large tanks) it was going to run me somewhere in the neighborhood of 1500$ per stand which is more than I wanted to put into the stand.

So I'm back to designing one from wood. I've made a number of stands from 2x4 etc... for standard tanks but nothing quite this long or wide. Having a little trouble finding a calculator to estimate load and deflection that will deal with the dimensions of the tank. Normally I'd use 2x6 rims for the bottom and top platforms and 2x4 for the uprights. In this case I wanted to maximize the area under the stand for ease of use and expandability in the future. Since the actual volume of the tank is relatively small for the square footage I'm hoping to be able to get away with 2x4 rims and 1x4 verticals(6 legs/posts). There will be no skin on the outside of the stand so the framing and the surface panels will have to handle all loads. For panel surfaces I would go with either 3/4" plywood or Advantek subflooring(23/32").

The stand itself would measure approximately 84x36x36(top surface) with the lower surface being 4-6" off the floor. Leveling feet of some sort would be used, probably leveling casters for convenience.

Anyone have experience with dimensions like these or have a link to a calculator that will let you enter custom span and support lengths?

Thanks.

 

[Timfish]

I would use 2x4 joists 8" to 12" apart with a 3/4" plywood top and a 2x4 joining them together at each end. I would use 2x4 cross supports made with 2x4s glued and screwed to make short L beams 8" to 12" from each end and in the middle. The legs also would be made with 2x4s glued and screwed to make L shaped legs and would be notched to fit around the joists and glued and screwed to both the joists and to the cross beams. Here's pics: