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

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

Works well! Very minimal cleaning of humidifier needed when using. Just drop in tank and forget about it. No respiratory issues.

This product is very good. I have the Pureguardian Ultrasonic Humidifier Model No. H965 which is cylindrical and a tank capacity of 1.0 gallon. I had a lot of trouble in the beginning about a year ago preventing mold. Spending hours constantly cleaning it. Trying just vinegar in the tank also didn't work before I found these antimicrobial aquasticks. I found right away that using just one for one-gallon tank doesn't work. You need to use both. But in addition you need to add 3 or 4 Tablespoons of distilled white vinegar or the mold still happens even with the two sticks. So put in both sticks and 3 to 4 Tablespoons of the vinegar each time you refill the tank daily with fresh water. When you empty the residue water, rinse out the bottom unit (which should be clean) and pour out the tank covering the hole with our hand so the sticks to do not fall out in your dirty sink!. Refill with clean cold water from the tap. This should last the 90 days they say for the sticks. Then do a full cleaning of your tank and base. Full cleaning for tank should be about 1/2 cup distilled white vinegar and several cups of water shaking the tank vigorously for 2 or 3 minutes to remove the residue. Then rinse several times the entire tank and refill with new sticks after 90 days. But remember: 2 sticks and 3 to 4 tablespoons of white vinegar. Hope this works for you.

don't use humidifier with out it. it really does keep microbe growth to minimum.

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

these work much better than I anticipated, I have them in two cool mist humidifiers in my house and it helps cut down on cleaning the inside of the water tank every two days - no mold or other issues starting to form!

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.