I switched to floatie took my auto chlorination off my plumbing and have had no issues with chlorine..in fact it keeps a better reading...unless you run your pump 24/7 the auto chlorination is not a good choice..just my opinion after owning a pool for over 25 years...I bought these floatie a off the Internet. On a site where the guy sells thE onEs tat pop up wheN ready for more tabs...he also sell this awesome brush...