Ballast System Purge for Winter

[gammapark]

Aside from physcially emptying the ballast bag, does the ballast system need to have water purged from it for winterization?
Is simply running the fill pump to blow air out of the hoses enough?

Chris

[Buttafewcoe]

I have a wet/dry vac that I use to suck water from the lines. Don't know if that's needed, but is what I do
.
B