Quote Originally Posted by CarlD View Post
Welcome!
I'm not the expert on winterizing pools with underground lines. Generally, though, I'm guessing it would be best if you could fill your underground lines with pool anti-freeze and plug them, disconnecting your pump and filter for the winter, and, perhaps, storing your cartridge in a cleaning bath, since it's in your basement already. You should be able to blow out the lines with a shop vac, rather than a compressor as vacs generally pack more volume and less pressure.

But...I'll let those who know better correct me.
One other follow up....there is really no way for me to get anti-freeze into the return line...unless I screw an "elbow" fitting into the outlet and pour it into that...is that how people do it?