The use of chlorine depends on the pool’s size and material. If it’s a small, plastic kiddie pool, you probably won’t be able to gauge how much disinfectant to add to the water to keep it at a safe level. However, for larger pools, the CDC recommends adding a filtration system and a disinfectant. This chemical agent usually comes in the form of bleach or chlorinating tablets, as well as CYA (Cyanuric acid), which keeps the chlorine in the water for longer.