Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Can this be used in ultrasonic humidifiers?
Document: We hoped these cartridges would reduce the amount of white dust from our ultrasonic humidifier, but have seen little improvement. Considering how expensive the cartridge are, they were a disappointment
I am not sure what can be about this product except that it works. I tried using the humidifier without one of these because I had another brand of ultrasonic humidifier and never had to use a demineralizer with it, but after about a month I had a thick grimy white discoloration on everything in my room. You can wipe it off, but what a hassle and since I have a TV and a computer in the room I don't want the mineral covering my electronics.
This item was just what my wife needed to keep our humidifier going! The price was right; the shipment was right on time; and, the product works perfectly!
This cleaner doesn't work as well as I had hoped. I still have slot of white dust when I use these.
These really work! My new humidifier is not forming any &#34;white&#34; residue anywhere. Highly recommend using these cartridges in a new humidifier.
These homedics cartridges were purchased for use with the Walgreen's Dual tank humidifier, which I purchased on Amazon.It is out of stock now, but it is the end of season. The dominant complaint in reviews was the white dust and difficulty cleaning thehumidifier due to calcification...Not a problem if you pop one of the cartridges in each tank..No sign of white dust, nor of calcification.These work like a gem. The Walgreen's dual tank humidifier is perfection with these gems.
The city I live in has very hard tap water. These didn't seem to help at all. After just a few weeks of using one in a 1 gallon humidifier, there was white dust all over my bedroom. (I stopped using the tabs, and started using purified water from a commercial water machine that uses reverse osmosis. I don't have problems now with white dust.)
THEY HELP CUT THE WHITE DUST.WISH THEY LASTED LONGER.RATHER GET IN STORE TO AVOID SHIPPING COST.OTHERWISE THEY ARE FINE.DAN THE MAN
Necesary
Keeps my hard water from messing up the humidifier. It also cuts drown on the &#34;white dust&#34; around the product
Answer: Yes.  I have used this in our for the last year.  I change them about once a month.  Because we use our ultrasonic humidifier every night.