Suggestions needed for building a 170G tank stand

[Toady2moo]

I'm a bit of a long term lurker but wanted to ask you more knowledgeable folk some questions about building a stand for a larger sized tank. In '09 I built a stand for my 6 ft 75ish gallon tank out of pine 2x4's and it has stood the strong and never moved. We've since made a stand for 2 and 4 ft tanks using the same plan (Based on the 'GARF Plan').

A few years ago I bought a 170G 6x2x2 glass tank which my oscar lives, however the stand is 38 inches high which makes the tank roughly 62 inches tall and hard to get into to clean so after years of frustration I have decided that I need a lower stand. The current one is made from 1.5 inch square steel tubing and we thought that maybe we should make a shorter one from metal tubing but as no one we know has a welder of any description it might be a bit hard to make.

But seeing photos of other MFK DIY stands I'm thinking that making one out of timber will not only be cheaper but I won't need to worry about finding someone to weld the metal. Can I use the GARF plan but instead of using 2x4's for the uprights use 4x4's? But they will be screwed on as well as having bolts added for extra strength (and I want to keep the 19mm pine top to it)


(This is the 75G stand upside down to show the supports)

Can it be done and will it be strong enough with 8 uprights made from 4x4's and still use the 2x4's for the top frame and top and bottom supports? Also should I get braces to keep the uprights nice and square?

 

[the_deeb]

I would avoid 4x4s - the have a tendency to warp. 2 x 4s will be strong enough. The best option would be to use doubled up 2 x 4s (or 1 x 4s) to make a sort of half-lap joint so that there is a wood connection running all the way from the top frame to the bottom frame. That way the top frame is supported by wood and not just bolts. The half laps will also help to keep your joints square and will resist racking better than your current design.

Keeping the uprights square and preventing racking is important. You can use angle braces or diagonal supports but the easiest way to accomplish this is probably to just skin the structure with plywood.

 

[Toady2moo]

Thanks for the reply the_deeb, nice to know about the 4x4's. I've been looking at other folk's designs and see that a lot of people add two 2x4's in the corners on the outside of the main 4 legs (by the looks of it this helps preventing the racking and any sideways movement).

Also with the plywood does it have to be structural plywood or can I get away with non-structural ply and would half inch ply be thick enough? I'll have to skin this stand to keep my cats out and I'm planning on adding some sort of metal L shaped brackets on the corners to stop any nibbling from my pet rabbits

 

[Toady2moo]

So, I've drawn up a basic plan for the stand (not to scale)

Yellow and Blue are pretty self explanatory, Red are the uprights but are covered at the ends by the two Greens due to the overlapping nature of the support timbers.

There won't be any bolts unlike my previous stand but instead using timber screws and wood glue to hold it all together