We have an outdoor whirlpool (hot tub from the Nietner company) with which we are very satisfied. At first we tried to treat the water with chlorine. But since we heat the water to about 37 to 39 degrees, we have to add a lot of chlorine to the whirlpool water. This is not good for our skin. Then I found the alternative: SpaBalancer. Top! Easy to use, clear and soft water and no more unpleasant smell. We are very satisfied with SpaBalancer and UltraShock.
Antje S.