Only tests 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 deeper shades of yellow if chlorine is present and will turn orange to reddish or even brown at very high chlorine levels. It is a subjective test differentiating the colors but it’s a good test for a daily check to confirm that there *is* chlorine in the pool even if confirmation of the exact amount is less important. This tester is often found in the less expensive test kits.