[yencabulator]

We have fairly hard water so they get chalky white and crispy in like 2 months or so, but replacing is still a little optional, the wick just starts slowly working less well. Minerals stuck on the wick aren't a health risk or anything like that. The base where the water sits is easy to wash and bleach when you feel like it.

[VorpalWay]

A tip here, if your wick is symmetric you can turn it upside down and get some more life out of it. My humidifier has rectangular wicks mounted at an angle, and only the top back tends to get a lot of minerals. I can thus turn them around and over in 4 different orientation.

Plus I have very soft water, so all combined I can get through an entire winter with just one set of wicks.

Still, I wish they made washable wicks out of fabric instead, so you could just put it in a bath of vinegar or citric acid for a few hours and then put them in the washing machine. In theory I see no reason they couldn't last for years.

[yencabulator]

These wicks are like tough paper. Yes, flipping the wick doubles the lifespan here. Also before it gets too bad, rinsing the wick dislodges the mineral deposits and slows down the buildup.