Quote Originally Posted by OUCH! View Post
So the one the kit comes with is not the inline TDS meter if not how many do I need?
There are different ones and it's really up to you. I have a dual inline and a handheld.

Water Source -> Pre-filter -> Carbon -> RO -> TDS #1 -> DI -> TDS #2 -> Purified Water

The handheld is to check your tap and whatever else you want. You don't 'need' any of these, but they certainly help.