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

How can I tell if it's working? It's been a few months of more or less daily use, and I still don't have any scale with my machine. I guess that means it works fine.

These are really great to keep your water clean and bacteria free which is so very important. They just drop in after cleaning the chamber.

Work as intended

They work great keep the machine. More cleaner

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.

Don’t buy the humidifier and you won’t need these

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.

Good

Exactly as advertised! Easy to install. 👍