The best option is to just cut back on pump run time. Cooler water temperatures and lack of swimmers will reduce chlorine demand, but unless the water is cooler than 60F, you will still be susceptible to algae.
I took the time to read your other posts and am impressed by your having done your reading as well as your general attitude ('As this site doesn't try to sell anything...' and 'Since there's no such thing as a dumb question...' 8) )
While most of the rest of us are worrying about getting the pool up and running for another season, you are looking ahead to whether or not your pool needs to be winterized
Given your climate and expected 'harshness' of the winter, you can very well do as John says and keep the pool open all year, with much shorter run time and fewer chem additions. A lot of folks in similar climates just like to be able to look out the window at their pool, even if they won't be swimming (lots of them say the cover is an eyesore and prefer to see the pool crystal clear). Winterizing a pool is a good bit of work and, if you don't have to close it (due to below freezing temps) you're probably better off leaving it open throughout the year. A word of caution, IF temps get below freezing, you must! run the pump to keep the lines and equipment from freezing!! Some folks have a temp sensor attached to the pump so that it will automatically kick on when it gets cold enough to possibly freeze - or, you can just be diligent about turning on the pump when frost is expected.
If you decide that you'd rather fully close the pool during the winter months, let us know and we'll tell you what you need to do :-D
Thanks for the help ... a couple of specific questions ... Is there a level of chlorine that should be maintained during the "inactive closing? Level of pH? Algae will be a problem as tempertures will fall into the 40's-50's. What should be done about the algae problem.
By the way ... I became a lifetime supporter today. I did it because all of you that are involved in this site have helped me become confident that after 4 years of pool ownership I finally know what I am doing and to go here if I don't!
You really want to maintain close to the same chlorine levels you do during the swim season to keep the algae away. Since the demand for chlorine will drop during the cooler weather, it won't take nearly as much addition or SWCG run time to supply the chlorine. The levels depend on your CYA level and your chlorine source.
BTW, I'm a regular visitor to Yuma. Was just there for a week and a half in January. Beats the heck out of July. I never knew what it felt like to be 119 degrees during the day or 97 degrees at 3am. Working outside, never sweat a drop, drank 3 Gatorade's and 4 bottles of water and went 14 hours without a bathroom trip. Not like home.
All I did to "close" was just run my pump when the temps got down to freezing. In Tucson, we are a little cooler than Yuma, so I didn't have to worry about algae. I didn't maintain my chlorine, just put some algaecide in at my last chlorine addition in November, and some in with my first chlorine addition in late February.