I did the 2x2 tent, also.
I reused my old buckets from the DWC days. Everything I build I try to make the whole thing without going to the store, or ordering stuff. These buckets are the bottoms of the ones I still had that I cut the tops off of for another build.
This drain and fill is temporary until I get it plumbed up to the drain and its own water tub. I'm basically going to do the same thing to my two 2x4's.
This tent is 2x2x4.
I had a lot of height to work with above the tent, so this table has been floating around my house for years. It is 20"x20". I put a 2x2 piece of plywood on top of it with brad nails and glue so that the tent would sit on top evenly.
Left over bottom part of the old buckets.
I used my calipers to scribe a line to cut. I want to save the middle parts, and not ruin them in case I want to use them later. Who knows.