PureGuardian Aquastick, Universal, Genuine Guardian Technologies Antimicrobial Humidifier Treatment, Ultrasonic & Evaporative, Fits All Brands, Reduces Odors, 2 Count (One Pack of Two), GGHS15

Seems to work well.

Where has this been all my life! I have a Venta Humidifier, and hated cleaning it, even after a long thorough cleaning, there would still be pink calcium deposits or mold left in between the spoke of the main wheel drum. I used vinegar and water to clean it, and still left with the residue (I try not to use chemicals to clean it). Low and behold, I found this item, decided to try it out. After a few weeks of using it, no pink build up. I love these sticks. I no longer get anxiety with not being able to completely get rid of the pink residue.

I was having trouble with mold in my humidifier here in Tehachapi, California. The air is very dry and I need to run this every night or I have sinus problems and very chapped lips.I was constantly fighting mold in my humidifier. Since using these almost none. But I still have to clean it. I only use distilled water. But prior to using theaquasticks, I was still getting mold. Black nasty stuff. Now I might get a small bit of pink mold in certain spots but it is easy to clean off. So you still have to check and clean I'd say once a month.Perhaps the mold some are still experiencing is of a more hardy type. I just don't know. For me, so far, they are working well.

These delay the onset of mold forming in my ultrasonic humidifiers. I will be ordering more.

Hard to tell if these do anything, have them in the humidifier, but I’m just trusting with the product says it does

Good for keeping out humidifier cleaner. They're so easy to use and definitely make a difference!

We are in Michigan, which has a whirlwind of humidity fun throughout the winter months. Depending on the year, we have a VERY dry house the entire season but other years, there's an ebb and flow with warmer than normal temps. This has made it challenging for us to maintain the four humidifiers that we typically bring out 3-4 months per year. If they are running nonstop, I've learned that the filters last longer but when humidity ebbs and flows, we get a faster accumulation of buildup and need to replace filters frequently. I've tried chemical additives, vinegar, and rinsing filters off to maximize life. It's super annoying and time-consuming and has been minimally effective.Last year I tried these on a whim and was delighted at how well they work. We had a mild winter that didn't require humidifiers to be constantly running and ALL of our filters remained clean for over a month. The typical pink/black/brown slimy and odorous filters that needed to be changed sometimes biweekly, we had a collection of slightly colored filters. This came at the end of our winter, so I pitched the filters but have high hopes for a much smoother experience going into another Michigan winter.I wish I had given these a chance before. I was a skeptic but no more as these have earned a coveted space in our Subscribe and Save lineup for annual home maintenance items.

I have large humidifier in my apartment and use it all winter. Black, sticky mildew built up inside the humidifier. I had to clean it often. I checked with the manufacturer about using a mildew preventer, and they discouraged using this product. The humidifier is so hard to clean that I rejected their advice and used it anyway. It prevented the build-up. I've used it for three years with no harm to the humidifier.