During the winter months, the amount of chlorine needed from your salt cell to keep the pool clean is reduced. This is due to the fact that it is difficult for bacteria to grow in cold temperatures.
Add Chlorine to Your Pool to Ensure a Clean Opening
In the fall, make sure to add chlorine and algaecide to your pool for over the winter. Don't add too much chlorine though.
Ideally, your pool's chemistry should remain as balanced as possible throughout the winter. Keeping everything balanced is easily accomplished by testing the water at least once per week. There's a low chance that you'll need to add chlorine as long as the pool isn't being used and there is no water circulation.
Shocking the pool during the winter months can certainly help to avoid a green swamp-like pool in the spring. It's often recommended. However, poor water balance or improper application can lead to unintended consequences, such as discoloration and damage to pool surfaces.
Super chlorinate with liquid chlorine or other chlorine source and add winterizing chemical kit to pool; allow filter to circulate to evenly distribute chemicals. (Use chemicals as labels indicate.) Use 1 gallon of liquid chlorine per 10,000 gallons of pool water.
Using a pool cover is one of the simplest but most effective ways to prevent algae from growing during winter. Algae requires sunlight to bloom, and a cover will ensure the pool water remains dark throughout winter. Plus, a pool cover will also prevent other leaves, bugs and debris from getting into your pool.
Most experts recommend waiting at least until temperature drops below 65 degrees Fahrenheit (18 degrees Celsius) to winterize your pool. However, if you can wait longer until your pool is below 50 degrees Fahrenheit (10 degrees Celsius), you will have a much lower risk of problems occurring.
Algae growth is stopped at temperatures below 40° F, but some algae can continue to survive, and like weeds in a lawn, can go dormant over the winter, coming back to life in early spring, weeks before you open the pool.
Closing a Pool with Green Water
No, not really. Why? Because closing a pool when its green is going to give you an even bigger problem in the spring or the next time you open it. When you are experiencing cooler, fall like temperatures, it takes longer for the chlorine and other chemicals to evaporate.
Keep it covered.
Covering the pool is a good way to prevent algae growth. The right cover keeps algae from entering the pool, but it also keeps leaves, bugs, bacteria, and dirt from decomposing in the pool, providing algae with food.
In warmer climates, Intex advises to keep your pool up, if you prefer. However, you must winterize the pool when keeping it full throughout the winter. If your area maintains tropical climates all year long, you may not need to winterize your pool at all, especially if you use your pool on a regular basis.
Your Cover is Too Old or Damaged.
If you had your pool professionally winterized, and your pool has turned green throughout the winter, this may be a signal that it's time for a new cover.
A swimming pool tarp, for example, that's black on both sides is like a giant solar panel. Because a black tarp on a swimming pool's water surface traps solar heat energy, it will eventually turn cool, refreshing pool water into a tepid, warm bath.
Do NOT let your pool freeze.
Not only can a thick sheet of ice damage your vinyl pool liner, but the expanding nature of freezing water can wreak havoc on your pumps and even burst your pipes - leading to thousands of dollars in damage to both plumbing and decking.
Your Pool Could Crack
Surface cracks are very common in pools that don't get winterized. Harsh conditions can lead to cracks as well as any water that is left inside the pool. That water will likely freeze and could lead to surface cracks.
Shocking kills any bacteria that might linger in your pool during the winter. We recommend shocking a few days before you close the pool. If that is not possible, make sure to shock the pool the night before you close it for winter.
Shocking your pool is easy: Use a shock treatment to bring your 10 to 12 PPM. Then, wait a day or two for the chlorine to come down to its normal level, about 1.5 to 3.5 PPM. Pro tip: For best results, shock your pool a few days before you plan to shut it down.
By simply adding algaecide to your water prior to closing, you can prevent algae growth from occurring during the cold, winter months which makes for an easier opening in the spring. You can apply algaecide directly to the pool water and allow the pump to continue to circulate for approximately two to four hours.
Even if you have your pool covered, some debris may still get in it during the winter. For this reason, you should consider running your pump on occasion whenever the outdoor temperature is between 35 and 65 degrees. Around four to six hours should be sufficient to remove debris and help promote good circulation.
Run your pool pump continuously when temperatures are near or below freezing. You don't need to run your heater, moving water likely will not freeze. Disconnect any aerators and lines to slides. Booster pumps for pool cleaners don't need to run continuously.