OTO

 

OTO will only test TC but it is a ‘bulletproof’ test that will not bleach out and will always tell you if there is chlorine in your pool. It will be different shades of yellow if chlorine is present and will turn orange to reddish or even brown at very high chlorine levels. It’s a good test for a daily check to see if there is chlorine in your pool and is the test that is usually found in 2 way chlorine/pH testers.