Read the label on the bottle. It will tell you if there is chlorine in it.You should always check your PH before using the water. If checked PH of bottled water that I bought at costco and it was over 8...if the PH is too high, you can use a little vinegar in it to bring it down if you don't have PH down.But always check the PH of your water before you use it if you've never used that source before.All water is not the same.