Winter Swimming Pool Closing Kits | Royal Swimming Pools

Pool closing kits bundle the chemicals you add when you shut a pool down for the season, so you are not buying and portioning each one separately. Each swimming pool closing kit pairs an algaecide and winterizer with a stain and scale remover and a dose of shock, sized for pools from 7,500 to 30,000 gallons. Chlorine and non-chlorine versions are available in every size, so the shock in the kit can match how you sanitize the rest of the year. Closing kits are often used alongside pool chemicals to address specific water conditions before shutdown. Many winterization plans also include pool blowers to prepare plumbing lines. For full seasonal protection, closing kits are frequently paired with winter covers.

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About Pool Closing Kits

Choosing the Right Size Kit

Closing kits are dosed by water volume, not by pool style, so an inground pool and an above ground pool holding the same water take the same kit. Sizes cover pools up to 7,500, 15,000, and 30,000 gallons. If you are not sure of your volume, our pool gallon calculator works it out from length, width, and average depth. A kit portioned for a smaller pool will not carry a larger one through the winter.

Chlorine and Non-Chlorine Kits

Every size is offered as a chlorine or a non-chlorine kit, and the shock is what separates them. Non-chlorine kits use a non-chlorine shock, which is the choice when you would rather not add chlorine to water that is about to sit under a cover for several months. Matching the kit to the way you already sanitize keeps the chemistry consistent through closing and into the spring.

Where the Kit Fits in the Closing Process

The kit covers the water treatment step, and it works best in water that is already clean and balanced. A full closing runs in order: clean the walls and floor, balance the water to a pH of 7.2 to 7.6 and total alkalinity of 80 to 120 ppm, add the closing kit, lower the water below the skimmer, clear the plumbing lines, then install the cover. Adding the kit before the water is balanced gets less out of it.

Pool Closing Kits FAQs

What do you put in a pool to close it for the winter?

Three products do most of the work. An algaecide and winterizer keeps growth down while the pump is off, a rust, scale, and stain remover stops metals and minerals marking the surfaces, and a shock clears contaminants before the cover goes on. A closing kit puts all three in one box, portioned for a specific pool volume, which is why most pool owners buy the kit rather than three separate bottles.

Do you really need a pool closing kit?

You can buy the same chemicals individually, and some pool owners prefer to. What a kit removes is the guesswork, since each one is portioned for a stated pool volume and there is no working out how much algaecide a 15,000 gallon pool needs. It also means you are not halfway through a closing when you find you are short of something. If you already keep winter chemicals on hand, buying separately is reasonable.

What happens if you close a pool without winterizing chemicals?

Water that sits untreated under a cover for several months usually reopens green. Without an algaecide, growth continues even at low temperatures, and without a stain and scale remover, dissolved metals and minerals can mark the liner and the surfaces. Little of that is permanent, but it does turn a spring opening into a cleanup job of shocking, brushing, and filtering rather than a quick start.

What is included in a pool closing kit?

Each kit combines an algaecide and winterizer, a rust, scale, and stain remover, and a dose of shock, with quantities matched to pool size. The non-chlorine kit for 30,000 gallons, for example, includes 1 pint of algaecide and winterizer, 1 quart of rust, scale, and stain remover, and 2 pounds of non-chlorine shock. Every size is available in a chlorine or non-chlorine version.

When should you use a pool closing kit?

Wait until the water temperature is consistently below 65 degrees Fahrenheit. Below that point algae growth slows enough for the treatment to hold through the winter. Closing while the water is still warm burns through the chemicals early and often means opening to algae in the spring. Closing too late risks freeze damage to plumbing, so aim for the window between the two.

Do you still need a closing kit if you use a winter cover?

A cover keeps debris and sunlight out, but it does nothing to the water underneath it. Algae and staining both develop in covered pools when the chemistry is left unbalanced, and a cover makes the problem harder to spot until spring. The two jobs are separate: the kit protects the water, the cover protects the pool from what falls into it. Most closings use both together.