Winter Pool Chemicals: A Buyer’s Guide

Time to close the pool!To close your pool for the winter season is to properly prepare your pool for the cold weather. A properly prepared pool will stay cleaner all winter long and make opening in the spring cheaper and faster.

There are a wide variety of winter chemicals that you can use to prepare your pool for its winter hibernation; these chemicals all serve the same purpose of compensating for having no filtration or circulation for 6 months.

winter pool chemicals buyer's guideKeep your filter running right up until closing day, in fact, running the pump and filter more during the time leading up to the pool closing would be good idea, to over-filter your pool water before shutting it down for half a year.


About a week before you close your pool, test your water and add any water balance chemicals needed like pH Increaser, pH ReducerAlkalinity Increaser and Calcium Hardness Increaser.

winter pool chemicals buyer's guideKeeping balanced water during the winter will help protect your pool surfaces, and help your sanitizers and other specialty chemicals to do their best job. If your water balance frequently needs adjustment, be sure to check it during the winter.

Pool Shock:

Pool Shock for closing the poolNow that you have balanced the water, you’ll need Pool Shock to remove any contaminants, so that your winter pool chemicals are more potent during those cold winter months. You can use Chlorine Pool Shock or Chlorine-Free Pool Shock; both will oxidize your pool water effectively, preparing your pool for your main winter pool chemicals.

winter pool chemicals buyer's guideIt’s best to shock your pool several days before closing the pool, to allow the sanitizer time to kill (6 hours) and time to dissipate (12-48 hrs), before adding other winter chemicals that may be affected by a very high sanitizer level.


After you have shocked your pool, you are now ready to start adding winter chemicals. The most important chemical that you need is the algaecide that will prevent the future growth. Algae spreads quickly and turns your pool water cloudy and green. Use an algaecide that controls this growth to keep your pool water clear and clean. Winter Algaecide is effective at eliminating and preventing all kinds of algae, namely green, black and mustard/yellow algae.

Winterizing Kits:

Winter Closing KitIf you want to take the guess work out of pool winterizing and make the pool closing easier and faster, we would recommend using a Winter Closing Kit.

Winter chemical kits are pre-measured for your specific pool size and contain everything you will need to prepare your pool for closing.

Specialty Winter Chemicals

Before you close your pool for the long winter months, you’ll want to ensure that your pool surfaces stay clean and are free from stains and discoloration. These clarifiers, enzymes and sequestrants eliminate micro-contaminants and tie-up metals in your pool water to keep your water and your pool surfaces clean and clear. They also allow your pool winter chemicals to work more effectively by removing excess particles.

Winter Clarifier:

buy Ahh-Some Winter ClarifierAhh-Some Winter Pool Clarifier is a triple action formula that sequesters minerals, coagulates tiny suspended particles into larger clumps, and then acts as a flocculent, sinking particles to the floor. Prevents stains by chelating pool water particles.

Stain Preventers:

If the water from your pool comes from a well, you know all about mineral problems. Iron, Manganese and Calcium can all cause colorful stains on pool surfaces. Copper, from eroding heat exchangers, copper piping or overuse of copper as an algaestat, can not only turn a blonde’s hair green, it can also turn your pool surfaces a teal color.

Natural Chemistry's Metal FreeMetal Free is recommended to control mineral staining, which can be difficult to remove. It sequesters the minerals, or binds them up in solution with a strong molecular bond, to prevent them from precipitating out of solution, and staining the pool surface (or turning your hair green).


Pool Magic & Phos-FreePool Magic & Phos Free combines the magic of enzymes with a phosphate remover to control algae by removing oils and contaminants that deplete your winter chemicals, while also removing phosphates – a major food source for algae. Also helpful in preventing stains in your pool.

Another good enzyme product is the Winter Ball. It slowly releases into your pool all winter long; helps keep your water chemistry balanced and consumes organics to prevent staining.


It is recommended to add Non-Toxic Anti-Freeze to protect your pool plumbing against freeze damage. Pool anti-freeze usually contains Propylene Glycol, and is poured into your pool’s plumbing lines to keep them safe from the damage that could be caused by ice expansion.

winter pool chemicals buyer's guideBe certain to use only Non-Toxic Pool Antifreeze, made from Propylene Glycol. Ethylene Glycol is for cars, and is not good for pools or people!

Take a pick from the products shown above or peek into our winter pool chemical store where we you’ll find an exceptional variety of winter pool chemicals. You are sure to find the chemicals that meet your needs and budget, and don’t forget a properly prepared pool will lead to a fast and easy pool opening next year!

Ayesha Aslam
InTheSwim Staff Blogger


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