Again it’s dependent on the local water hardness. It was very low when we had Lake Michigan water.It's interesting people have been able to use tap water in their humidifiers. I did this for 1 season and eventually clogged my furnace filter with white powder. It also coated plastic surfaces with a fine film of white dust. Of course I didn't realize it was the humidifier at first or I would have shut the thing down.
I would too if it was available, but it isn't...I would stick with distilled
Project farm is not a reputable source for any testing (especially engine oil). If anything Consumer Report would be a more reputable source.Check out the Project Farm video on water filters. Most are a waste of money. The Zero Water filter is the more reasonably priced one that actually works. I bought one and the problem was the filter would fill up in a short amount of time, making it not cost effective. There are a lot of dissolved solids in the water here. If yours doesn't, it might be a good option. I've gone back to filling up my 5 gallon jugs at the grocery store for $1.99 from the Glacier machine. It's not perfect (I test it with strips and a dissolved solids meter) but way better than my tap water.