[rames14]

As Jim said, they are not accurate. We installed SeeLevel gages. They adhere to the outside and measure in percentage. Do not leave your valves open all of the time. There have been reports of nasty bug issues by doing that. You have the rotomolded tanks. They are much stronger than older style. Try dumping once a week. Also, use the gray water to flush after dumping your black tank. Definitely don’t leave your black tank open. That will end up with the dreaded pyramid.