ProTec PC-2 Humidifier Tank Cleaning Cartridge, 2-Count Packages (1 pack of 2 cartridges)

These work really well keeping the tank from getting slimy. I think some poor reviews are because people think they are a substitute for cleaning the tank. You still need to clean the tank regularly! A small but necessary job . . .

This was one of the best investments I ever made. I bought a new humidifier, a Honeywell with outstanding reviews, and the filter gave me trouble. In a little over a week it smelled mouldy in a really foul way, and within 2 weeks the filter literally fell to pieces in my hands. These are expensive filters to last such a short time. I changed the filter and bought 2 ProTec balls, one for each tank. It worked like magic! No smell, no moldy discoloration. These things are wonderful! If you're sitting on the fence, jump off it! Run and buy one of these things right now!

These little doohickeys actually last a lot longer than the manufacturer states. We kept one in both of our humidifiers for years and never had any indication of mold or mildew. There are others that look like these things, but you need the ones that are made with silver. We only replaced ours because we replaced our humidifiers after more than a decade of use. I can't say yours will last that long, nor can I recommend you never change them. I can say they work great.

Works great, keeps humidifier bacteria free.

Got these as I was finding goopy stuff in my humidifier water. These work perfectly - keeps the water (and the filter!) clean.