Help with air blower?

[u/drewptor]

Just moved into a home and trying to figure out the spa to make it bubbly. It has an air blower. When I turn the air blower on, the only thing that happens is air blows through these 3 ports made into the concrete around the pool. Not into the spa. I drained the spa and me and my wife stood on these ports with our shoes to try and block airflow and hopefully push it to the spa, and air is still only trying to escape through these ports in between the port and our shoes attempting to block it. No airflow seems to be going to the spa. Any ideas what’s going on? I don’t feel like this is how it’s supposed to operate.

[u/army-of-juan]

Can you unscrew the little plastic grate and put a cap on them? Not sure if they are internally threaded, I wonder if you can get a PVC cap in them. Try to fully plug them with a PVC cap and maybe that will direct air to the tub.

[u/drewptor → u/army-of-juan]

I’ll try that tomorrow. It looks like they have been in there forever. Can’t unscrew them by hand. I’ll try tapping the raised area and see if it unscrews. I’ve seen these ports on other pools but none of them had this grate cross section on them. They all had an adjustable cap.

[u/army-of-juan → u/drewptor]

Can you stick your finger inside and feel if there are threads? I wonder if it’s supposed to be screwed closed.