Dreo Scale-Inhibitor Cartridge 3-Pack for Humidifiers HM735S, Prevent Mineral Build-up, Extend Humidifier Life, Safe Material

they work excellent, using reverse osmosis water with these cartridges i have no foul smell or green water, the first time using a humidifier I've had no issues (Dreo)

Easy to install and do what they say! Good value for the money.

simple to install the new filter and haveing well water I changed the filter as the instructions say, every month.

Drain the water in your tank, pull up the plastic tubing, pull off the old cartridge, insert the new cartridge. Easy enough.On the box, they recommend replacing the cartridge every month (depending on usage and water quality).Mine are active 24/7 during the winter and my water is relatively soft so it's only a guess when I should replace it.If you were to replace every month, that would cost $20 x 4 = $80 (3 in a box).After two years it's more expensive than the Dreo HM735S itself.A bit expensive, if you ask me.So, when performing an internal clean, remove the cartrige and soak it in hydrogen peroxide 3%.Sure, that won't rejuvenate the cartridge or remove scale but it will kill fungus and bacteria.Rinse the cartridge out and return it for another month or two.....or three...Whatever you do, check your humidifier internals to spot fungus or bacteria before it overtakes crevices and hard to reach places. Nobody wants fungal/bacterial spores being shot up into the air, just so you can breathe them.

Our Dreo humidifier came with one of these demonization filter cartridges. I ordered many months worth just to have on hand, they work great to prevent the white dust that often comes with tap/hard water used in coolmist humidifiers. I love the humidifier and we buy these cartridges again and again.

What a disappointment. I purchased the Dreo humidifier, it leaked after one month of use. After many conversations with Dreo, they convinced me to allow them to send me a replacement. I have only had it maybe a week. I bought the filters b/c the initial humidifier spewed white powder over my entire house. It got on items in my kitchen cupboards, the floor, EVERYWHERE. So I bought 2 packages of these filters so they would last the winter months, this year and part of next. Well, I had the SAME PROBLEM. We emptied the filtered tap water out and just filled it with distilled water......no more white powder. My recommendation is to never put tap water (even though mine was double filtered) in it. Always use distilled water.

It works as intended and described. No complaints here

Bought these for our Dreo humidifier - which is the best one out there…have tried several that died. Others left a white chalky residue everywhere & these eliminate that completely. Very impressed