At some point i'm going to have to park my eriba against a wall for a couple off days and need to fill the flush tank in advance before i start using it. Does anyone put any antifreeze of any form in the flush tank.
When i'm using the caravan it will be warm enough it's just the few days either side of my trip when i might struggle to have time to drain etc

I wonder if you could add some salt?

I wasn’t sure how much the flush tank holds or how much use but when the caravan is in place I won’t be able to that side of the caravan and just wondered how seals & electric pump would cope with a glycol added, if there’s any risk I’d have to re think it

I don't use the flush tank. I fill a bottle with pink mix and flush with that. The flush on our loo is the most pathetic little squirt.