Using a pressure washer on the outlet side of the DI tank will help to get the city water off quicker. Remember that it is advisable to only use DI water for the final rinse, to wash off the city rinse water. We recommend using the lowest possible water pressure that your pressure washer will work with. Higher pressure will not improve the end result and will only use up your resin quicker. If you can Buy Spotless Deionized Water System Online at an affordable price from our website spotfreefinish.com.