Product review (4 stars): Honeywell helps with our well water
We have well water that contains some minerals, but is not normally a problem.  I use a Vicks UV 99.9% Germ Free Mist Humidifier in my bedroom.  It holds 2 gallons and we are putting 2 gallons into the air every 24 hours during dry winter weather.  This pad needs to be cut down slightly to fit properly.  I use it for 5-7 nights before replacing it and there is still some mineral sediment that collects under the pad.  However,I can see that it does help to contain much of the mineral content.  I ran out and used my humidifier without the pads for a couple of nights and I could definitely see many more mineral deposits throughout the base of the unit.  I expect it will extend the life of my humidifier and I will continue to use them regularly.  I found that they are hard to find and Amazon was the best solution to purchase these pads.