Th OP asks a question about use of the Kirmuss and gets told to sell it. Very helpful.
My friend had a Kirmuss and always drained the fluid after a session. He cleaned around once a month. That being said, if you are using it every day, I'm sure you could keep it filled and no harm will be done. Does the fluid pass through a filter in the Kirmuss?
I use a DeGritter, I change the water if it sits for more than a week. I change or clean the filter before each cleaning session. I agree with mijostyn that having a cleaner that is be ready at any moment to clean is a big advantage. The DeGritter/Kirmuss does not meet that criteria. The Degritter uses fans to dry, the Kirmuss relies on microfiber towels, the Clearadio has vacuum.