How to Store Pool Chemicals and Gear for Winter (Without Turning Your Garage Into a Science Experiment)

The pool is closed (or at least napping), the leaves are winning, and somewhere in your garage there's a shelf of half-used pool chemicals quietly plotting. Okay, they're not plotting. But store them the wrong way for a few months and they can lose strength, leak, or react with each other in ways nobody wants to explain to the fire department.

Good news: storing pool chemicals and gear for winter is easy once you know the ground rules. Here's how to do it safely, based on guidance from the companies that make this stuff.

Quick heads-up: The label on each product is the final word. If anything here disagrees with a label or a manual, follow the label.

Rule #1: Never mix chemicals. Ever.

This is the big one. Different pool chemicals can react violently with each other, and some combinations can cause heat, toxic gas or even fire. That includes different types of chlorine. Mixing two kinds of "the same thing" is not a fun shortcut.

• Keep each product in its original container with the label on it. No pouring leftovers into an old coffee can or "combining" two half bags to save space.
• Use a separate, clean, dry scoop for each chemical. A scoop with a little residue from one product can start a reaction in another.
• Keep chlorine and acid apart. Store chlorine products (tablets, granules, liquid) and acids (like muriatic acid or pH decreaser) on different shelves, ideally on different sides of the room. If a container ever leaks, you don't want it dripping onto its worst enemy.

Pick a good spot

Your chemicals want what most of us want in winter: somewhere cool, dry and not too dramatic.

1. Cool, dry and out of direct sun. Heat and moisture break chemicals down faster and can make some of them unstable. A damp corner of the pool equipment pad is not a storage room.
2. Well ventilated. Chlorine and acid can give off fumes, and those fumes are hard on metal tools, equipment and your lungs.
3. Off the floor. Put containers on a shelf or pallet so they stay dry if water gets in.
4. Away from flammable stuff. Keep pool chemicals away from gasoline, oil, paint, fertilizers, lawn chemicals, cleaning products and anything else that burns or reacts. Yes, that means rearranging the garage. Sorry.
5. Locked up or out of reach of kids and pets. Curious little hands and curious little noses are not a good match for pool chemicals.

Seal it up tight

• Close every lid all the way. Moisture sneaking into a container of granules or tablets can start them breaking down, and humid air is sneaky.
• Check containers for cracks, bulging or leaks before you put them away. If a container is damaged, don't try to repair it or transfer the contents yourself. See the "what to toss" section below.
• Wipe up spills right away with plenty of water (unless the label says otherwise), and never sweep spilled chemical back into the container.

Watch out for freezing

Some pool products don't like the cold any more than you do.

• Liquids can freeze. Things like algaecide, clarifier, enzyme products and some test reagents can be ruined or separate if they freeze. If your garage or shed drops below freezing, check the label and move liquids somewhere that stays above freezing.
• Test kit reagents and test strips should come inside too. Reagents are sensitive to heat, cold and light, and they don't last forever. If yours are more than about a year old or look cloudy or discolored, plan on replacing them in spring. Fresh DPD reagent #1, reagent #2 and reagent #3 are a lot cheaper than guessing.
• Keep test strip bottles capped tight and dry. Strips that sat open in a humid garage will happily tell you whatever they feel like. A new bottle of 4-in-1 test strips or chlorine test strips in spring is cheap peace of mind.

Liquid chlorine: don't stockpile it

Liquid chlorine (sodium hypochlorite) loses strength over time, and it loses it faster when it's warm. A jug that's been sitting since August won't be nearly as strong by spring. Use up what you have, store any leftovers cool and out of the sun, and buy fresh when the pool opens. Think of it like milk, not like wine.

Don't forget the feeders and floaters

Chlorine tablets sitting in a feeder or floater all winter, with no water moving, can give off concentrated fumes and be rough on nearby equipment.

• Empty the chemical feeder or chlorinator when you close the pool or shut the pump down for a long stretch. Wear gloves, follow the feeder manual, and open it in a well-ventilated spot, standing back from the lid since fumes can build up inside.
• Rinse it out with water (water only, no other chemicals) and let it dry. If the lid, o-ring or tubing looks worn, now's a good time to swap it, like this feeder accessory pack or replacement chlorinator tubing.
• Floating dispensers come out of the pool, get emptied and rinsed, and dry out before storage. If yours is cracked or faded into a sad shade of not-blue, grab a new floating tablet dispenser for spring.
• Already shopping for a better setup next season? An inline feeder like this automatic chemical dispenser or an off-line above-ground chemical feeder makes daily chlorine a lot less hands-on.

Storing the rest of your pool gear

Chemicals aren't the only things that hate winter. Your gear will last a lot longer if it doesn't spend the season baking, freezing or getting run over by the car.

• Robotic cleaners: Rinse with fresh water, let them drain and dry completely, and store them indoors out of the sun and away from freezing temperatures. Uncoil the cable so it doesn't get kinked, and keep it off sharp edges. A caddy cart keeps the whole setup tidy and off the floor.
• Suction and pressure cleaners: Rinse them, drain the hoses, and store them somewhere dry and shaded. Check for cracked hose sections and worn parts so you can replace them before spring.
• Vacuum hoses: Drain them, coil them loosely (tight coils create permanent kinks), and store them out of the sun. If yours is already stiff and cracked, it's ready to retire. A fresh 1.5" x 25' vacuum hose will be waiting for you.
• Poles, brushes, nets and vacuum heads: Rinse, dry and hang them up. Sunlight is what really ages plastic, so store them in the shade.
• Your test kit: Bring it inside with the reagents. If it's missing pieces or the reagents are old, a full complete water test kit is a nice way to start the season fresh.

What to toss (and how)

Old, unlabeled, leaking, clumped-up or contaminated chemicals aren't worth saving. But don't just dump them.

• Don't pour chemicals down the drain, into the street, onto the lawn, or into the regular trash.
• Don't mix leftovers together to "get rid of them all at once." See Rule #1.
• Take them to your local household hazardous waste drop-off, or call your city or county to ask how they handle pool chemicals. Many areas have free collection days.

The short version

Keep chemicals in their original containers with the lids on tight, store chlorine and acid apart, keep everything cool, dry, ventilated and away from kids, pets and anything flammable, bring liquids and test reagents inside before they freeze, empty your feeders, and store your gear clean and dry. Do that, and spring opening will start with swimming instead of a mysterious smell in the garage.

Want to restock before spring? Browse our pool parts and supplies and get ready while everyone else is still hibernating.