To keep the ice off? Gonna try sumpin' this year. A small spray bottle with 50/50 mix of Isopropyl and water. More so to use on the bottom of my locator. Tends to get quite a build up on the Genz box. We'll see.
I heard water soluble antI freeze made with vegetable products works to keep whole clear.. used for rv fresh water systems.. but I don't like putting nothing in a lake that is not there already!