Just to add to my previous post about our 5 stage Reverse Osmosis system.
Along with the system we purchased a fairly expensive ($80.00) digital reader which tests the water for "suspended particles only!"
Our city tap water reads between 135-140 parts per million
The best commercial bottled water reads at 40 parts per million.
Our Reverse Osmosis water here at home reads at 3-4 parts per million.
Now our tester will not test for Fluoride but we did have a sample tested at a lab after installing our system.
The results were good, actually perfect.....Zero Fluoride/copper/lead/Mercury/zinc/ etc etc.