Plywood and Steel Aquarium

[Takeo]

Hi all

I'm playing with the idea of making a new tank. I've been looking at previous plywood buildings and they all are reinforced with just timber. Has anyone made one with a steel frame which the plywood 'tank' would sit inside? Where I'm from timber is quite expensive and usually low quality so I was thinking of using mild steel box section instead. I've made a few drawings in CAD to show off my idea.

So if you have any recommendations or see anything that could potentially go wrong with my idea feel free to let me know.

The dimensions are 3m x 1.4m x 1m so it would hold around 4000 Litres.
The gaps in the frame are 30cm x 30cm.
The plywood is 3.6cm thick
The acrylic is 5cm thick

Thanks

 

[BIG-G]

Im no steel worker, I can't even weld.
But one thing I notice is all the legs. If this tank is placed on an uneven surface its going to be very hard to level and support all those legs. Maybe the legs should be tied together along the bottom with a solid section across each row of legs.
You may not need all the legs either just something to think about.

 

[Takeo]

Im no steel worker, I can't even weld.
But one thing I notice is all the legs. If this tank is placed on an uneven surface its going to be very hard to level and support all those legs. Maybe the legs should be tied together along the bottom with a solid section across each row of legs.
You may not need all the legs either just something to think about.

To be honest I wasnt overly worried about that since its going on a freshly poured concrete floor but it does make sense to incorporate a flatter bottom. About having less legs I was thinking that it would reduce the likely hood of any flexing. My main concern was any flexing or thermal expansion differences between the materials.

 

[David R]

This is the only one I recall seeing; https://aquariumworld.nz/forums/topic/39913-stand-aquare-tube-size-for-2tons/?page=2#comment-519170

Not quite the same size or design as you're looking at building, but might give you some good ideas. FWIW Warren lives in an earthquake-prone part of NZ and wanted to make sure his tank would stand up to a good size shake, so while his numbers may seem OTT compared to what many people get away with there is a good reason for it (he's also the guy who did the calculations that run most of the 'aquarium glass thickness calculators' I've seen online too).

Just looking at it, given how short the legs are on your tank I think there's a better way to do that if you don't want the tank too far off the ground. Maybe even a concrete plinth poured for the tank to sit on? And if you do go with legs you definitely need diagonal bracing and to have something that ties them together. The other thing that strikes me immediately is that 1.4M wide is a funny width given that the standard ply sheet is 2.4x1.2. IMO 200mm extra width isn't really worth the hassle of mucking around with that little bit of extra plywood and the extra joins it involves.

Keep us updated, I really like the idea of a steel framed ply tank, I'm interested to see what you come up with.