Your best bet is to go with a Pentair Intellichlor Salt system. I am a service & repair tech and have found these to be the most reliable. You need to also think about the time you have to run your pool as the pool only generates sanitizer when the pump is running. I would do 1 system and in the dead of summer you can add a little chlorine if needed but if you run it enough it should not be a problem. Salt systems only draw back is that you will always be battling the ph levels in the pool but adding acid is very easy.
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