As Peter said, your cya is high. You can either run higher than normal chlorine results as a result or you can do a partial drain and lower your cya. Also, what type of chlorine are you using? I would suggest just using bleach. Trichlor and dichlor will raise your cya and cal-hypo will raise your calcium hardness level which is already high. Don't want it any higher or you may start to have cloudy water issues. Welcome to the forum.