Algodoo

This is a great idea. If shower water was filtered and reused, than a tremendous amount of energy could be saved. Estimate energy usage of a non-recycled shower using the following:

WATTS = TEMPERATURE RISE (°F) x GALLONS PER MINUTE x 147
WATTS = TEMPERATURE RISE (°C) x LITERS PER MINUTE x 69.8

For a 2.5 gpm shower using water heated 60°F greater than ambient, the energy usage is 22,000 watts. There is probably no appliance in your house that comes close to using that much energy. That's 22kW going right down the drain.

Actually, the amount of wattage going down the drain will not be as bad as a regular shower if the water were filtered and reheated. The reheated water will only need to increase the number of degrees above the waste water temperature to bring it back up to the "comfortable" shower temperature. Eventually, when finished with your shower, you can keep the heated water in an insulated storage unit to be used later for another shower or for washing clothes. Eventually, the filter will need to be back-flushed to clean it, but that could probably be done with cold water. A closed-loop water heating system is MUCH more energy efficient than the standard way we typically heat, use, and then dispose of water.

Yes. That is what I was trying to say. You just did a better job of saying it.