I just had a question about closing my in-ground pool this year. Last year I had the pool store come out and close it as I had only had the house/pool for a week's worth of use and wasn't ready to even try. I watched them do it, I opened the pool this year, and I feel confident to close it myself. The other thing is I'm going to close the pool while keeping the spa open, so I'm only blowing out half of the lines. If something goes wrong and I find one of my valves do not close completely, I'll go about doing the spa as well and fix it for next year.
Anyways, the questions I had related to the actual chemicals I'd need; the procedure I'm familiar enough with. I read the Pool School post as well as the sticky regarding closing the pool. So shocking the pool before closing it, and cleaning it are obviously easy to follow. However, last year I know they added a bunch of chemicals (I know the pool store is just there to make money), and I wanted to find out which ones were actually needed. I had told them not to add calcium but he did anyways and my levels were off the charts all summer.
So I believe the idea is to go into winter with 'balanced water', and since I've been managing the pool myself this year, I know that things will be fairly balanced. Then you shock it to kill any remaining algae that may be there. Since the water should be cold enough when you start, no new algae should spawn after the shock. Then the posts say to use polyquat per bottle instructions I assume to prevent algae growth when the water temp rises. Lastly, I know the pool company added a 'winterizing shock' (chlorine free) and some other chemicals (like calcium) to my water before they closed it. Are any of these needed?
I don't want to waste a ton of money on stuff I don't need, but I want to make sure I don't skip anything. Is polyquat really the only chemical you need for winterizing? And is it a special kind of algaecide, or can I find it at walmart or Sam's Club or something? To note, I have a solid cover, so the water that is in there when I close is fairly close to the water I have in the spring.
As a side question, where all do I need to put antifreeze in? I assume I put it into both skimmers before I seal them up. Then I put them in bottles as floaters in the skimmers in case water gets in there when it rains. What about the return lines, any way you're supposed to get it in those? If I'm keeping my pump/filter running in the winter for my spa, is there anywhere else I need to put it? And any easy way to guess how much I'll need? Last year they used 3.5 gallons, but I kept the bottles they had in the skimmers, so I assume I can reuse those.