I don't weep my foam brushes, I use Windtrax's recirculating system which runs warm liquid, either water or antifreeze, I use the latter, down your hose lines and back up. I made it into a closed loop system (with a vent for expansion) and run it whenever it's below freezing. My brushes are used a lot in the winter time and thus I need them operational. Also, a side benefit is that the warm lines run down my troughs keeping them warm. I used to have a lot of freeze ups in the winter before I put this system in. Last winter (first season of use) I had zero freezes. I really didn't notice my electric bill go up. Just using a Procon pump and water heater filled with an antifreeze solution. I don't circulate 24/7, I cycle the pump on and off with my PLC. Something like on for 4 minutes, off for 1, etc..