John was very knowledgeable on his products he would use. I had worked with raising the PH on other substrates for 25 years. When he made references to this action, I was sold on him performing our work . 1,500ft2 (large area)... hard worker and gives 125%. He did not leave until "he" was satisfied. He came back a week later when I had found area rugs and wanted them cleaned...... price was less than renting a smaller machine and me performing the work..... John knows this cleaning work ..I will use his service again soon on another house. he is the man for carpet care