Maybe six or seven years ago, I got one of those large Zerowater carafes that filters out dissolved solids to a 99+% rate (and also, funnily, it reduces Chlorine and Fluoride). A few years later, the city of Chicago then sent all us taxpayers a smaller Zerowater carafe and six filters gratis. (Well, actually, paid by our property taxes.) Chicago has one of the best water systems around, but sometimes, I can really smell the chlorine in the shower and coming out of the kitchen tap.
ZW also provides you a meter that measures dissolved solids. Depending on where you are, tap water usually has around 100 to 200 PPM; ZW reduce that to zero, and you’re supposed to periodically test the water so you know when it’s time to change the filter.
I’m telling you all this because I also used the meter to measure the water being filtered out of the fridge dispenser, and it had the exact same dissolved solids levels as the tap water, and when i changed the fridge filter to new and ran five quarts through the dispenser as instructed, it still had the same readings as water out of the tap.
So, I’ve started to think the whole fridge filter thing is a sham.