I’m not quite a year into hot tub ownership. It has been 3 1/2 months since my last purge with awww one and refill. After my purge my Cl usage dropped way back. Heck, I could even skip a day during the week and not add any liquid pool chlorine. Now, I’m adding a lot more. Trying to stay between 5-7 with CYA 40. Water is balanced. Clear and smells great. Same daily usage. Is this a sign I need to shock or purge and do a water change? CC is .5