Question re: my new RO/DI filter
 

Just setup a new Captive Purity RO/DI last weekend and intially the TDS meter measured ~172 ppm on the water IN, and 0 ppm on water OUT.

I shut the water off after my reserve tank was filled, and ran the RO again last night to top-off my tank. Had it on for about an hour and the reading OUT was around 7 as opposed to 0. Any thoughts on that?:question:

You must have a small amount of contamination in your top-off tank, probably not enough stressing over.

You should empty your RO tank about 3X before using the water for the first time, and the tank should be before your DI filter