When doing telephone work and running through lots of apartments and dorms, I came across what I feel is a great stand for those who move a lot or don't have tools/space for building. It may not feel too high class but it is certain to work and it is easy to do with a minimum of fuss.
Set a concrete block under each end of the tanks. Use the 8X8X16 blocks and turn the holes facing up. Then lay a couple 2X 6,8, or 10 inch across between the blocks to make a shelf. Add a second layer of blocks and a second layer of 2X for the top of the stand. Add a cover of your choice fabric if you don't like it all out in the open and leave an opening flap at the front.
Portable, each part is easy to move in, even when using buses or trains, easy to set, plenty strong and easy to take with you when you move. They work great for college folks in dorms.
For tools, it just needs some way to assure all four corners ar elevel and even to avoid twisting the tank.