Knowing your water balance will determine what shock will work best for you. Testing your water before hand will save you time and money and keep a healthy, maintained pool or spa. We recommend the TF100 Test kit as it includes everything needed and is very accurate.
Chlorine CYA Chart
Note: Chlor-free can show up as CC in a CC test. Introducing a reagent to the test will solve this problem. Our recommended test kit, the TF100, has everything you need, including a reagent.