The most effective way to kill algae in a pool is to shock it with a high dose of Chlorine. While algaecides help prevent future growth, a massive dose of chlorine is required to eradicate a live bloom.
To kill pool algae quickly (usually within 24–48 hours), you need to super-chlorinate the water and manually remove the dead spores.
Shock Your Pool
Unless, of course, you're dealing with chlorine-resistant algae like mustard algae or black algae. This is one of the few times you may need to consider using an algaecide. But even then, it should be used in addition to chlorine or other sanitizers, not instead of them.
Use a pool brush to vigorously scrub any pool surfaces covered in algae, including the walls, floors and steps. Apply a green algaecide according to the directions on the label. Let the water circulate for 24 hours, then brush the pool surfaces again. Vacuum or backwash to remove any remaining dead algae.
Clear pool water with a green tint may be from pollen, chlorine-resistant algae, or most often from a too-high pH level. When a pool's pH is over 7.8, even high levels of chlorine destabilize and cannot sanitize, and metal in your water and pool components can oxidize, giving off a greenish hue.
Yes, pool shock is the most effective way to kill algae. By adding a highly concentrated dose of chlorine to your pool, you rapidly spike the free chlorine levels to overwhelm and kill algae spores, clearing up a green pool.
Alternatives to Chlorine In Pools You Could Consider
Algae growing over larger sections of the pool or suspended in the water will require a strong dose of chlorine pool shock — or granular chlorine — to kill the algae. Shock the pool to a level of 30 ppm. This usually requires 4 pounds of pool shock per 10,000 gallons of water.
To deal with algae, you should consider adding water lilies, hornwort, or duckweed to the water body (note: Duckweed can become a problem if there are excessive nutrients in the water). These plants prevent algae from getting the nutrients and sunlight they need to grow by consuming them for themselves.
Dawn dish soap itself does not chemically kill algae. However, it acts as an excellent surfactant. It breaks the surface tension of water and lifts algae off surfaces, making it highly effective when used alongside mechanical scrubbing or as an additive in DIY exterior cleaning solutions.
Finding the best algae remover depends entirely on where you are treating it. For outdoor surfaces (patios, decks, and siding), the top-rated choice is Wet & Forget Outdoor Concentrate, which removes algae without scrubbing. For swimming pools, Doheny's Super Algaecide Plus is highly effective at killing and preventing all types of algae.
Yes, you can add liquid or granular algaecide directly to the pool by slowly pouring it around the deep-end perimeter while the pump is running. Always keep the filter running for at least 24 hours to ensure the chemical circulates evenly.
Dead algae in a pool typically turns gray, white, or a dull, pale brown. It often settles as a fine, dusty layer on the pool floor or clouds the water, rather than clinging to the walls.
If your pool is cloudy blue, then you successfully killed all the algae in the water. Now you can use a pool clarifier if you want to clear it more quickly, but even if you do, be sure to run the filter for at least 24 hours to get the dead algae out of the water, and ensure the shock has fully dissipated.
Chlorine is still one of the most effective killers of algae so doing a super-chlorination of 10-20 ppm of chlorine can go a long way towards wiping out the algae. Liquid chlorine is an ideal shock for algae because it is fast acting and does not add cyanuric acid (CYA) or calcium to the water.
Yes, you can add algaecide to your pool without a pump, but it is highly discouraged. Without a pump and filter, the water does not circulate, causing the chemicals to sit heavily in specific spots, which can stain your pool liner or result in patchy, ineffective treatment.
The fastest way to eliminate algae depends entirely on your setup. Generally, the quickest approach relies on manual removal, an appropriate chemical shock or algaecide, and eliminating the root cause (e.g., light and excess nutrients) to prevent it from returning.
To clean a green pool in 24 hours, you need to overwhelm the algae. Start by scooping out debris and brushing the walls vigorously. Next, balance your pH and add a triple or quadruple dose of chlorine shock at dusk. Finally, run your filter continuously for 24 hours, cleaning or backwashing it when the pressure rises.
For heavy soiling, dilute 2 parts water to 1 part GK Greener Kleener. For light to medium soiling dilute 3 parts water to 1 part GK Greener Kleener. Easily apply the formula to the affected area using a garden sprayer or a brush. Allow the product to work (ideally overnight) and then wash your tools.
You can get rid of algae quickly by vacuuming and brushing your pool, balancing your pool's water chemistry, and then shocking and filtering your pool water. Just be thorough as you clean your pool surfaces. If you leave behind even a small number of algae spores, it won't be long before they regrow and bloom again.
Be sure that the pennies are 1982 or older. The chemical reaction of the copper in the pennies keeps the water clear and algae free. I went through an old coin jar and found plenty. Before 1982, pennies were 95% copper and 5% zinc.
A dirty filter at closing can lead to algae and cloudy water come spring. Take time to deep clean now and start the season ahead.
To get rid of dead algae in your pool, you need to clear the cloudy water and remove the settled particles. First, test your water and balance the pH, then run your filter continuously. Finally, use a pool vacuum to clean the pool floor, ensuring you vacuum the waste directly out of your system.
If your pool shock isn't killing algae, you likely haven't used enough product to overwhelm the bloom, or chemical imbalances are neutralizing the chlorine. To clear the water, you must maintain high chlorine levels continuously, balance your pH, and keep your filter running to remove dead matter.
If the pool algae keeps coming back, it's often due to lapses in regular maintenance or environmental factors that introduce more spores into your pool. Regular water testing and treatment with an algaecide can help reduce these occurrences.