Steve
Use a solar cover during the Spring and Fall to extend your swimming season, but buy a good quality winter cover if you close your pool during the Winter.
A good solar cover can extend your swimming season by several weeks each Spring and Fall. We have all seen advertisements for 15 degree increase in water temp with the use of a cover, but we usually see a 5-7 degree increase in water temperature with the cover on our pool. The solar cover with a heater or heatpump can extend your season by 4 months. We open our pool two months earlier than our neighbors and we swim long after they have stopped using their pools.
We tried using the solar cover as a Winter cover only once and the results were a disaster for our pool and for our cover. We will not make that mistake again. The leaves and debris stuck to the top of the rain soaked cover and formed a slimy swamp during the winter. In the Spring, we spent hours trying to remove the now very heavy cover without spilling the leaf muck into the pool and without tearing the cover. We ended up with loads of green and brown slime from the decomposed leaves, algae and debris in our pool. It took hours to clean out the solid debris, several gallons of bleach for several days and almost a week of constant run time and several backwashes for our DE filter to return the water to it's former sparkle.
The layer of moisture on the cover throughout the winter would freeze and thaw even in our mild SE US Winters. We believe this shortened the life of our solar cover. It may have simply been the extended time in the Sun or the decomposing leaves that caused the cover to break down. If you use the solar cover as a winter cover then it will see a much shorter service life. We now store our solar cover during the Winter and it lasts much longer.
We don't use a Winter cover because we don't close our pool.
Here is how we manage our pool throughout the seasons in a climate that is very similar to Houston. We generally stop using our pool in late October or early November, but we don't close it. During the Fall, it takes about 10 minutes each day to clear the skimmers of leaves and to scoop out the floating leaves with a large leaf net. The Polaris 280 clears the leaves that sink to the bottom so the debris bag on the Polaris needs to be emptied daily. This LEAF MADDNESS only lasts through November and from December until March we do very little to the pool.
We keep our water balanced throughout the Winter months, just like the rest of the year. When water temps are below 50; the SWCG does not operate, so we add a little bleach or toss in our "Puck Duck" to maintain our normal free chlorine level. CYA levels increase only a few ppm with the use of the pucks for a couple of months during the Winter and normally decrease slowly due to backwashing and rainwater dilution throughout the season.
We believe it is easier and more cost effective to keep the pool open in our climate and to do a small amount of pool upkeep during the non-swimming season rather than have the added work and costs of closing and opening. It is not necessary to test the water as frequently during the off season, but it is still a good investment to spend a little time and a few dollars on testing regents and water balance chemicals to prevent any potential problems.
When Spring arrives, usually around April, our water is already balanced. There are no algae blooms or water issues to deal with. No opening kit or special chemicals are required. There will be no need for powdered shocks, algaecides, clarifiers, floculents, cleaners or enzymes. We simply add the solar cover, turn on the heatpump, and within a few days... swim.
