Water tank specs

[W.olly]

Is there anyone one here than give me an idea on specs for building a water tank with a steel frame and inner clad plywood, the imfo i need is on the steel frame as in the bracing, i was thinking, as i have a load of 20mmx10mmx1.6mm steel, was to weld a length to get 20mmx20mm to kae the brace bars and all around infact. the barce bars would be 450mm apart sides and bottom, then clad inside with 18mm plywood and GRP laminate with 2 layers of tissue to water proof etc.

By the way its going to hold fish so one side will be minimun 16mm glass, i say this to save the sking of what i am building, i have looked on other self build forums but not many go this rout as they all use timber to build them which takes up tank volume. every inch matters....so i have been told

 

[pedrobedro]

Save yourself some grief and build it out of wood. It will be easier to fasten your plywood sheets to it and your 20x20x1.6mm home made box will take more fabricating than it will be worth as a structural component. You don't give enough detail like how big the tank will be overall and what kind of capacity. It's going to hold water, the fish are incidental and the water is going to be heavy so don't skimp. The resin will also need to be waterproof so you need to use the expensive stuff. Someone may have more idea of what you need if you put more detail into your description.

 

[W.olly]

Oh yes, i always seem to forget the important bits lol

the tank will be 9x3x3, water level will be around 33 inch, and around 500 gallon water capacity,if i make it from just 18mm ply then you think it will be strong enough, all the ones i have seen have 4x2 timber frame which takes up alot of space, also with just ply then i think it would need a lot of layers of GRP to strenghten it more.
I am not in a rush to hab it up so the steel frame/weight/pressure bearers would be a problem and part of the fun realy