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I add chlorine and by the next morning I do a test and it's zero again My Ph is okay cai've only had the hot tub two weeks Can anyone help
Are you putting enough chlorine in where it's 3 PPM at 20 minutes after you add it? You shouldn't add "some" you need to have amounts so you know how much to add. My tub usually has a residue amount 24 hours later so I'm confident the tub is santized, you should be shooting for some chlorine in the morning.
Thanks for your help I can relax now
You didn’t mention if your tub is brand new or new to you for just two weeks. If your tub is new I seriously doubt you have a biofilm build up in your plumbing.