outside temp and electrolysis

since im going to do this outside what should the min temp be ?will i make a enuff heat to keep my mix free of ice?

my vat is freezing.i thought that maybe i could put in a horse water warmer like u get at tsc. would this work?

On the presumption you are talking about a vat used for electrolytic derusting, I, being naturally lazy and averse to working in the cold, would just wait for warm weather to solve the problem. A watering troth heater should work, but I'd remove it when the tank is being used, just to prevent possible problems.