Winterize main drain pool

[ibra0078]

Hi guys, moved into a new house that has a above ground pool, I am about to winterize the pool and I'm pretty sure what to do but the only thing I am not sure is the main drain. They installed a main drain that is connected to the pump with a shutoff value on the pump. When I drain the pool below the jet and remove all the lines, how would I close the pipe going to the main drain. When I detach it from the pump I am pretty sure water will be rushing out, I was thinking to blow air in that line however when I stop blowing air wouldnt the water simply pour out of that line without capping it? If I cap it woulndt the water in the line freeze? Thank you

[Denniswiseman]

Yes it would freeze
If you shut off the valve can you remove the pump and blow back the water
Alternatively you could block the main drain with an expandable plug and then disconnect the pump and drain the line