Slightly confused...how do I blow out the lines?

[edweather]

I have 2 skimmers and 2 returns. The skimmer lines join at a valve on the inlet side of the pump, and the return is from the filter divides somewhere underground for the 2 returns. After I drain to below the returns, how do I use my shop vac to blow out the lines? Thanks.

 

[Bama Rambler]

Block off one skimmer and one return with a gizmo or plug and blow from the other one, then swap the plugs and blow the other ones.

 

[edweather]

OK thanks. Should I leave the multiport valve on "filter?"

 

[bk406]

OK thanks. Should I leave the multiport valve on "filter?"

Put it to Reciruclate. You dont want to blow air through the sand. Which is what it would do set to filter. Remove the drain plug at the bottom of the filter to let all the water out of the filter.