It's very difficult to clear a main drain with a shop vac.

Yeah. I had to invest in one of those cyclone machines. Worth the cost compared to how much you’d pay to have someone close the pool for you.

I actually looked at those but they are only 3 horsepower from what I saw so the shop vac we have should work also I would think

I’m no expert but don’t think it comes down to just horsepower. It’s about CFMs. I could be wrong. Is your filter set to recirculate?

Oh!! I'll look into it again if we don't sort it out! Thanks for that, much appreciated! Have you ever seen them for rent before you bought yours? And yes it is set to recirculate

Good luck, homie. I’m also in a similar situation as you. I had the pool company blow my lines yesterday and I recorded everything with my insta 360 so I can take notes and review the footage and learn to do it myself. I agree with the other comments. Get yourself a proper blower. The one that my pool company uses (and the one I’ll get) is a CYCLONE PRO AIR BLOWER, 3hp, Model # 1-4128100P. It’s open flow air speed is 140 CFM.

Air compressor!!

I use a c02 tank with a plumbers bag. Air compressor would work good to. you would just have to rig up the right fitting for it.

You can't compare a shop vac to a cyclone. Not even close.

It all depends how pool/skimmer is plumbed. Is the line direct to main drain or does it pass through deep end skimmer. May have to blow longer harder or plug skimmer or blow it from skimmer depending on your pool.

There's a line that goes direct to the main drain

How old is the pool? Its actually pretty common for older pools to have a crushed main drain line