There is no reason to take a shower using a bag hanging from a tree, it is the worst idea possible.
I have used a camp type shower for the last 5-7 years, please stop with the hanging shower types, these camp shower bags do not work.
You turn the thing on, and you have only the amount of time it takes to empty, there is no good way to budget water.
1. The handles do not turn the water on and off easily.
2. There is no way to shut the water off with one hand.
3. The thing is heavy, and has only one purpose.
4. There is no way to use to heat, other than solar.