1. Using the POOL MODE button ,switch the RC9 to manually off.
2. select the MAINT option and the following screen will be shown;
3.press NEXT button twice so that the middle button displays DOSE .press DOSE button .
4. Select YES .You will be give the option to dose either Acid or Chlorine, pick the one you are wishing to dose. You will then need to set the dosing time/quantity using the up and down arrows to the right of the screen. You can choose to dose by volume of liquid or time period. Once you have set volume/time to be dosed, select ACCEPT.