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

I've been using these for a couple of weeks and they seem to work well as intended - which is to extend the amount of time in between humidifier cleanings. I've noticed that the slimy film I would notice on the lid doesn't even start appearing for a couple of weeks - which is a week or more longer than without. I think some of the bad reviews are from people who wrongly believe they never need to clean their humidifier or who think they don't have to do it very often. Wrong. You still need to clean the humidifier. This just lets you go a little longer in between cleanings.

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 work very well. I have been running two cool mist humidifiers all winter long for many years because of problems with dry eye and a winter cough. Keeping them clean from bacterial bio film has always been a hassle. I discovered this product in early December and put one in each humidifier. I haven’t needed to clean them once. I highly recommend them.

Works great, keeps humidifier bacteria free.

I thought when you use this thing, you don't need to clean as often, but I found that there are orange water stain and some black stains building up after a couple of weeks. I would rather use bleach and vinegar to do cleaning and s disinfecting weekly. I will not buy again.