Works very well with tap water. Much cheaper than buying distilled water since I use it every day. I'm also happy to not have to use so many plastic containers. I wish the filters were available in stores where the humidifiers are sold.
Don’t bother. Tried using this with tap water and filtered water and I still had white dust accumulations on everything within 10 feet of my Crane Drop humidifier in a matter of one night. Price is ok, but unfortunately it doesn’t work at all for me.
After just one week's use, the humidifier started growing red grime/bacteria. We even use the Crane filter. We clean it every week with vinegar, as recommended, but is never goes away and just continually gets worse.