What Chemicals Should I Use To Winterize My Pool?

It's time to start preparing your pool for the cooler months as the hot days slip away. Learn how to winterize in-ground and above-ground pools by reading this guide.
After a summer of fun in the pool, make sure to properly "winterize" it before closing it for the season. These actions are part of basic pool care, and they will help guarantee that your pool is in great shape when you reopen it.
When Should You Begin Winterizing Your Pool?
Begin winterizing your pool once the pool season is over. Typically when the temperature begin to drop below 65 degrees F or lower, you'll want to consider closing your pool down unless you plan on heating it to extend your pool season.
If you begin winterizing your swimming pool too soon, you may have to contend with algae, which thrives in warmer temperatures. Allow yourself a few days to complete the pool winterization process, as there are multiple steps that must be completed over several days.
Do You Need To Winterize Your Pool In Dallas?
Typically the weather in Dallas never drops below freezing for very long. However, last year, the DFW region saw unprecedented damage caused by a later winter freeze that lasted for several days. The best advice for local homeowners who do not utilize their pool or spa during the winter is to close it down for the season. If you're not the type of person who uses their pool or spa except for in the summer months, winterizing your pool is a good call.
Swimming Pool Winterization
The easiest way to purchase the right chemicals for winterizing your pool is to simply purchase a pool winterizing kit. If you opt not to use a kit, make sure you have all of the necessary chemicals before you begin winterizing your pool:
- Alkalinity Increaser / Decreaser
Sodium bicarbonate will raise the total alkalinity, and pH when it is too low. Conversely, sodium bisulfate will reduces alkalinity and pH when it is too high - Calcium Hardness Increaser
When calcium is too low, the water can become corrosive. Conversely, when it is too high, you may see cloudy water and floating particles. Scale can also build up in your pool equipment clogging in. - Pool Shock
Shocking will raise the free chlorine level to a point where contaminants such as algae, chloramines and bacteria are destroyed. - Algaecide Clarifying Enzyme Supplement (optional, but recommended)
Clarifying enzymes are typically used in conjunction with algaecide and chlorine. These enzymes can eliminate dead algae from the water.
Clean your pool before winterizing it. Vacuum the entire pool, clean the walls, and skim the top layer of the water. A clean pool makes it much easier to maintain optimum water balance. It also guarantees that nothing is left behind to nourish any algae or mold that may form during the winter.
Chemistry Levels For Closing Your Pool
Before you start closing your pool, take a few minutes to test the water. pH should be between 7.4 and 7.6, and alkalinity should be between 100 and 150 parts per million (ppm), with 125 ppm being optimum. Make sure the calcium hardness is between 175 and 225 parts per million, and the chlorine is between 1 and 3 parts per million.
If your water is too acidic, add a base to balance it out. To bring your water back into equilibrium if it's too basic, add a pH increaser. Add alkalinity increaser or sodium bicarbonate to your pool water if the alkalinity is wrong. If it's too high, add muriatic acid to bring it down. If your pool water is excessively hard, you can purchase chemicals to soften it, or just dilute it with fresh, non-hard water. Is the water too soft? A calcium hardness increaser or simple calcium chloride can be used to raise the level.
Chemically Treating Your Swimming Pool For The Winter
Using a granular oxidizer to shock the pool gives it an excellent start for the winter. It removes pollutants and impurities that could discolor the pool or eat your winter water chemicals. If you're going to use chlorine pool shock, do it 5-7 days before you plan to close the pool.
Use a winter algaecide that is designed to "hibernate" until the water temps rise again the following spring. Copper algaecides in high quantities should be avoided.
Sequestering compounds, such as stain and scale treatments, are used to keep metals like copper and iron from oxidizing and staining pool surfaces. They also prevent pollutants from combining with salts and calcium minerals to generate dirty scale.
Winter pool enzymes are designed for frigid temperatures and long-term efficacy, staying active until late spring. Winter chemicals should last for the whole 6-8 month off-season if dosed correctly and added to a clean and clear pool. When the water begins to warm in early spring, however, a pool with algae or an ill-fitting cover may benefit from more algaecide or chlorine-free pool shock. Before opening the container, pull back a side of the cover for 2-4 weeks to assess the need for more chemicals.