I try to do it everyday but at least 2-3 times per week. It's a used compressor so the first time I did it there was a fair amount of rusty colored water, but after that it comes out mostly clear so I'm hoping that's a good sign. The compressor itself seems to be very clean with minimal wear. I started using royal purple compressor oil as well and finally got some anti-vibration pads under the feet.. running like a champ.