Review on Aprilaire - 35 A1 35 Replacement Water Panel for Whole House Humidifier Models 350, 360, 560, 568, 600, 600A, 600M, 700, 700A, 700M, 760, 768 (1-Pack) by Raquel Perkins

As with most home appliances I am unfamiliar with, even simple maintenance can be intimidating. I will say that changing this filter was very easy. I recommend turning off the humidifier for 24 hours. This helps in many ways. First, of course, you don't want it to fire when you're messing with it. Second, you need a dry filter to limit the clutter. And thirdly, and perhaps most usefully, if you change it up and reassemble it, you can turn it on and it should work pretty quickly. Allows you to ensure your water hose and drain line up. Will drip where it shouldn't if there's a problem