The basic steps for adding chlorine tablets

Chlorine tablets dissolve slowly in your pool water and keep it safe to swim in by killing bacteria and algae. You add them using a chlorine floater (a plastic device that holds tablets and drifts on the surface) or a skimmer basket (the basket inside your pool's filtration system). Most home pools use one of these two methods because tablets release chlorine steadily over days rather than all at once.

The process itself takes about five minutes. You place a tablet or two into whichever device you're using, set it in the water, and let it work. The tablet slowly dissolves as water moves around it. You'll check the chlorine level every few days using a test kit and add more tablets when the level drops.

Key Takeaways

  • Chlorine tablets go into either a floating device or your pool's skimmer basket, not directly into the water.
  • A floater works best for above-ground pools and pools without skimmers; a skimmer basket works for in-ground pools with built-in filtration.
  • Test your chlorine level every two to three days using a test kit, and add tablets when the reading drops below 1 part per million.
  • Never handle tablets with bare hands—use a tablet holder or tongs, because chlorine can irritate skin and damage pool surfaces.
  • Tablets take 24 to 48 hours to fully dissolve, so add them in the evening and retest the next day.

Using a chlorine floater for above-ground pools

A chlorine floater is a hollow plastic container, usually round or rectangular, with a dial or cap that controls how fast the tablet dissolves. You fill it with one or two tablets, close it, and set it in the pool where it drifts with the current.

To load a floater: unscrew or unclip the top, drop in one tablet (or break a large tablet in half if needed), and close it again. Most floaters have an adjustment dial on top—turn it to a lower number if your chlorine level is rising too fast, or a higher number if it's dropping too slowly. Place the floater in the deep end or near the return jet where water circulation is strongest, so the tablet dissolves evenly.

Check the floater every few days. When the tablet is mostly gone, open it, remove any small pieces, and add a fresh tablet. Rinse out any white powder or residue before refilling.

Using your pool's skimmer basket

If your pool has a built-in skimmer (a box on the pool wall that pulls water into the filtration system), you can drop tablets directly into the skimmer basket instead of using a floater. This method works well for in-ground pools because the tablet dissolves as water flows through the basket toward the filter.

Open the skimmer lid and lift out the basket. Place one tablet in the basket, then replace the basket and close the lid. The tablet will dissolve over the next 24 to 48 hours as the pump runs. You don't need to adjust anything—the flow of water controls the dissolve rate.

Check the basket every few days when you test chlorine levels. Remove any leftover pieces before adding a new tablet. If your pump is off for more than a few hours, the tablet won't dissolve, so turn the pump back on as soon as possible.

Testing chlorine levels and knowing when to add more tablets

You need to test your pool's chlorine level every two to three days. Buy a test kit from any pool supply store—they cost $10 to $30 and come with test strips or a small bottle with color-changing reagent. Follow the kit's instructions: dip a strip in the water or add drops to a sample, then match the color to the chart on the box.

The safe chlorine range is 1 to 3 parts per million (ppm). If your reading is below 1 ppm, add a tablet. If it's above 3 ppm, stop adding tablets and let the chlorine naturally decrease over a few days (or run your pump longer to speed circulation). If your level stays too high even without adding tablets, you may need to use a chlorine reducer, which a pool supply store can recommend.

Chlorine levels drop faster in hot weather, after heavy rain, and when the pool gets a lot of use. You may need to add tablets weekly in summer or every two weeks in cooler months. Keep a log of your test results so you can spot patterns and adjust your routine.

Safety and handling precautions

Never touch chlorine tablets with bare hands. Chlorine is a strong chemical and can burn your skin, damage pool surfaces, and bleach your clothes. Always use a tablet holder (a plastic tongs-like tool made for this purpose) or regular pool tongs to pick up and place tablets.

Store tablets in a cool, dry place away from sunlight—a garage shelf or pool shed works well. Keep them in their original container or a sealed plastic bucket. Do not store them near other chemicals, especially acids or pool shock, because chlorine can react dangerously with some substances. Keep tablets away from children and pets.

If a tablet breaks or crumbles, use tongs to pick up the pieces and place them in the floater or skimmer. Do not leave broken pieces on the pool deck or in the grass, where they can bleach or damage surfaces. Wash your hands after handling tablets, even if you used tongs.

Troubleshooting slow or uneven chlorine levels

If your chlorine level stays low even after adding tablets, the tablet may not be dissolving properly. Check that your floater's dial is set to the highest number (fastest dissolve rate), or make sure your pump is running if you're using a skimmer basket. A pump that runs only a few hours a day will dissolve tablets slowly.

If your chlorine level spikes suddenly, you may have added too many tablets or your pump is running too fast. Remove the floater from the pool for a day or two, or take the tablet out of the skimmer basket and let the chlorine naturally decrease. Test again after 24 hours.

Heavy rain, algae growth, or a lot of swimmers can all cause chlorine to drop quickly. If you're adding tablets more than once a week, consider running your pump longer each day or switching to a larger floater that holds two tablets. A pool supply store can help you choose the right size for your pool.

When to call a professional

If your chlorine level won't stay in the safe range no matter how many tablets you add, or if it keeps spiking, there may be a problem with your pump, filter, or water chemistry. A pool service technician can test your water more thoroughly and recommend whether you need to clean your filter, adjust your pump schedule, or add other chemicals.

If you notice cloudy water, algae growth, or a strong chlorine smell even with the right chlorine level, stop using tablets and contact a pool professional. These signs usually mean something else is wrong with your water balance, and adding more chlorine won't fix it.

Frequently Asked Questions

Can I put chlorine tablets directly in the pool without a floater or skimmer?

No. Tablets dissolve unevenly if they sit on the pool floor, which can damage the surface and create dead zones where chlorine doesn't reach. Always use a floater or skimmer basket to keep the tablet moving with the water.

How often should I add new tablets?

It depends on your pool size, weather, and how much the pool is used. Most pools need a new tablet every 3 to 7 days. Test your chlorine level every 2 to 3 days and add a tablet when the level drops below 1 ppm. Keep a straightforward log to see your pattern.

What if my floater sinks or won't stay on the surface?

A floater that sinks is usually full of water inside. Empty it completely, dry the inside, and refill it with tablets. If it still sinks, the air chamber may be cracked—replace the floater. They cost $15 to $40 and last several years.

Can I use chlorine tablets in a hot tub or small spa?

Tablets are too slow for hot tubs, which need faster chlorine release. Use liquid chlorine or granular shock instead, which dissolve in minutes. Ask your hot tub manual or a pool supply store which form is safe for your specific model.

Do I need to remove the floater when people are swimming?

You can leave it in, but many people remove it during heavy use to avoid swimmers bumping it. Just put it back in after everyone leaves. If you remove it, the tablet stops dissolving, so plan ahead—add the floater back in the evening so chlorine is ready by the next day.