BONECO EZCal Pro A100 Humidifier Cleaner & Descaler, 14oz Single use, eco-friendly humidifier cleaner and descaler Use for your mid-season deep cleaning. Ideal for pre and post season maintenance. Use on ultrasonic, steam, evaporative or air washer humidifiers EZCal Pro is safe to use on other humidifier brands. Directions: 1. Remove humidifier filters from unit; 2. Fill base with EZCal solution and equal part water; 3. Let it sit for 30 minutes; 4. Rinse thoroughly before use