Jake Dimmock, co-owner of the Northwest Patient Resource Center medical marijuana dispensary in Seattle, works on balancing the pH level of the soil used to grow new medical marijuana plants on Nov. 7, 2012. (Associated Press)

Photo by: Ted S. Warren

Jake Dimmock, co-owner of the Northwest Patient Resource Center medical marijuana dispensary in Seattle, works on balancing the pH level of the soil used to grow new medical marijuana plants on Nov. 7, 2012. (Associated Press)