I' closing my in-ground, completely-separate-from-pool, spa. I drained the spa completely. Then, I blew out all of the jets and returns, the skimmer and the main drain, added antifreeze to the lines as a precaution, and plugged all the lines. I also cleaned and emptied the filter and blew out the heater. Finally, I removed and drained the main pump and two jet pumps and stored them inside. All the valves are shut off. I plan to add back water to the bottom of the hot tub to about 6 inches below the skimmer to make sure there is no heaving. I have two questions left:
1) Do I remove the drain plugs for the filter and the heater for the winter? Or do I try to add antifreeze and keep the plugs closed?
2) There is some sort of air intake pipe (pvc) that comes up through our bushes. Does this need to be blown out? I'm not sure I understand exactly what it does.
Thanks for your help.