I can see black spots in the tank, and I'm not sure if they're from the silver ion cartridge or mold. The instruction manual (which I checked online) states that the white and black powder coming from the silver ion cartridge is not a problem for use. Also, there are limescale marks on the rubber parts and the bottom. ※Please feel free to ask any questions or request photos of anything you're concerned about before purchasing. Top-Fill Ultrasonic Humidifier UTK-230-W White 2-WAY Specification: Top-fill & Bucket-style Tank This compact ultrasonic humidifier has a simple design that matches any room and is perfect for interior decoration. It's a convenient 2-WAY specification with top-fill and a bucket-style tank, allowing you to either pour water directly into the tank from the top by removing the lid or take the tank to the tap. The mist doesn't get hot, so there's no risk of burns, and it operates quietly, making it suitable for bedrooms. The silver ion cartridge keeps the water in the tank clean. The tank is removable, so it's easy to clean. DC 24V (using a dedicated AC adapter) Humidification Method: Ultrasonic Humidification Level: High / Medium / Low Power Consumption: 20W (when running on high) Suitable Room Size (Approximate): Wooden Japanese-style room: 6.4m² (3.7 tatami mats) / Prefabricated Western-style room: 10.1m² (6.4 tatami mats) Humidification Capacity: 230mL (when running on high) Humidification Time: Approximately 13 hours (when running on high) Tank Capacity: 3.0L Cord Length: Approximately 1.5m