I bought a cottage that had a Hot Tub already. I have never owned one so knew next to nothing about maintenance. Went out and bought a bunch of chemicals recommended by the local spa store and soon ran into chemical $@!#%. I rent the cottage a majority of the time so the tub gets used extensively by many different people. By the time I bought the Aero-Spa, my water was green and smelly. I decided to give it the ultimate test by not starting with clean water but running the unit continuously. After 5 days my water was crystal clear. Amazing. I switched to the 2 hrs twice a day recommended schedule and the next week my bacteria test came back negative. The water is still clear and the bacteria is still negative 2 weeks later. I will be forever grateful for this device. Also, the customer service while I was getting everything just right was outstanding. Thank you