Martik wrote:
Is there any way to do this? I would like to get it down to 5-10gals
to
encourage wasteful kids from taking long showers.

If they do counter your move, consider a compromise: Put a tankless
point of use water heater at the shower.

Consider the Stiebel Eltron:

http://www.plumbersurplus.com/Produc...CategoryID=180