Ditto, our Headhunter reads in 10% increments and works well. The black tank one plugged up once, but all I had to do was push the manual button in the bay a couple of times to put pressure in the line and it blew out whatever was in there. I have the three tank version and the fresh water is also hooked up to the Headhunter pump so if the fresh tank gets too low, it turns off the pump so it won't get damaged.