How to stop condensation forming on ceramic toilet cistern?
Condensation will form where warm moist air meets a cold surface. A thin film of washing-up liquid reduces the surface tension of the condensation so preventing it forming droplets. It’s still there but it is spread out. If you recently renovated your bathroom in accordance with UK building regulations, you already have a vent in there, though that will only help reduce, not prevent condensation. The only ways to STOP it would be to stop releasing water vapour in the bathroom (impossible if you are using it) or fill the toilet cistern with warm water – a complete waste of expensive energy – or isolate the cistern from the atmosphere in the room (eg built-in cistern or insulated). The answer is probably to live with the condensation and wipe it off from time to time.
