I have an 18' AG. Here in Texas it may get below 30 just a few days out of the year, so I don't close the pool, I just trim back how long the pump runs and make sure it runs during the freezing temps. However, I always get junk in the pool, and still always having to clean it. So I was wondering this year, can I put a cover on, but still run the pump to circulate the water and inject chlorine?

If I can, do I need to put a pillow in the middle to keep the cover up off the water?

I did that my first year and it works pretty well. I used (2) 4' x 15' pillows tied centered in the pool and had no problems. Since I've never done it without pillows, I can't comment on how that would work.

Cool, thanks. Is there an issue with just using an innertube vs a pillow?

The reason I used the pillows was to divert the water and leaves to the sides to make it easier to pump off the water and remove the debris