What size air compressor will blow out my lines?

I am trying to winterize my pool for the winter. I have had pools in years past but just moved into this house this year. I have an inground pool with about 12,000 gallons. It is only 5" deep in deep end. The pool has 1 skimmer, a main drain on bottom of deep end and 2 returns to pool. The pool has a heater and a DE filter. I have a nice valve set up at the pump pad and a fitting I can tie into for blowing out.

So i bought all of my winterizing chemicals drained below skimmer level. PH and Alkalinity were good. I was going to use a shop vac I had to blow everything out. I jury rigged a set up and began to blow. Some water moved but never saw air coming out(All valve except skimmer closed meaning no other way for air to go but where I directed it). I though OK maybe this shop vac is not big enough. I went and got my leaf blower. it really has some Omph to it. same thing. I ended up calling it quits for the night.

So I have an air compressor. It is a 1.5HP with a 3 gallon tank. It has a max pressure of 150 psi. Will this be big enough. My thought was to run to the store in the morning and buy some fitting so i can tie it in. Does anyone have any experience in this? Is it volume or pressure I need. i have red conflicting things on this topic (as well as to whether I should have drained below skimmer). Any help would be appreciated. I really do not want to pay a pool company $300+ to do what I know I can do myself.

I don't have an IG pool and thus cannot help with your question. Maybe this 'bump' will get some more views from someone who can answer it for you.

Welcome to the Pool Forum.

Thanks for the bump watermom. I used the air compressor the next morning and it worked like a charm! Set it for 25 psi and I was done in no time.

Great! Glad it worked well for you.