For light green pools, use 1 lb. of shock treatment per 10,000 gallons of water. So, for 25,000 gallons of water in pool, use 2.5 lb. of shock treatment.
Can you put too much shock in a pool? SKIMMER NOTES: It's unlikely but it could happen. It would take a lot of shock to really make the water unsafe for swimming. The best way to make sure you're safe to swim is to test your pool water and make sure free chlorine levels are between 1-4ppm for healthy swimming.
Important: Even if you normally use non-chlorine shock, you must use chlorine shock to kill algae. If your pool is dark green, meaning you have a larger algae infestation, we recommend shocking the pool three times. And if the color of your green pool is reminiscent of a dark, spooky swamp, shock it four times.
A good rule to remember is to use one bag of shock (1 gallon of liquid chlorine) per 10,000 gallons.
You need to raise the level of your chlorine – shock the pool – and maintain that high level until all the algae is dead. This may take 3 to 4 days.
Although, if you overdo the shock treatment, you risk getting green hair from chlorine due to the excess chlorine oxidizing the copper in the water. You can execute a shock treatment with a few different types of pool shock, just be mindful of how much you're using.
Pools can immediately turn green after shocking when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.
A pool filter should be run for a minimum of 6 hours after shocking a swimming pool. This is to allow the filter to clean the water and give the shock enough time to fully mix with the pool water. Running the filter after shocking for 24 hours to 7 days is necessary if the pool has a large amount of algae.
Typically for granular shock, you'll need one pound for every 10,000 to 13,500 gallons of pool water.
Algaecide should be used after each shock treatment, so it has a better chance to support your chlorine as it works its magic. Be sure to shock your pool first, then when the chlorine levels of your pool return to normal, add the correct amount of algaecide to several places around your pool while your pump is running.
Backwash only as needed. Brush the pool vigorously, several times after shocking the pool. Do not use a solar blanket until chlorine and pH level are normal. If chlorine level drops to zero within 24 hours, Repeat the shock treatment.
Shock Your Pool
To eliminate any contaminants or chloramines in your cloudy pool water, add a high dose of chlorine by shocking your pool. If the cloudy water in your pool is due to a pool algae bloom, you'll have to double or triple shock depending on the type of algae you have.
The free chlorine levels might be low.
But be careful—adding too much chlorine in pool water can cause those metals to oxidize and turn the pool a different shade of green.
Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly. Chlorine tabs (placed in a chlorinator, floater, or skimmer basket) maintain a chlorine residual in the water. You do need to use both tabs and shock.
It Should Not Be Done Together
This is because when you mix chlorine and algaecide together, it renders both of them useless. Hence, you should first shock the pool and wait for the chlorine levels to fall below 5 PPM. Only then should you introduce algaecide to get the best results.
Baking Soda and Green, Blue, or Yellow Algae
You'll need to use an algaecide to kill the algae and superchlorinate your pool to clear the water. After this treatment, test your pH and alkalinity and add baking soda to raise alkalinity to at least 100 ppm and pH to between 7.2 and 7.8.
One bag of In The Swim cal hypo is always 1 pound, therefore, you need three bags to triple shock a 10,000-gallon swimming pool and get rid of algae. *For liquid chlorine or sodium hypochlorite with 12.5% chlorine, add 10 ounces for a 10,000-gallon pool to raise free chlorine (FC) by 1 ppm.
The best time of day to shock your pool is in the evening. This is because the sun's rays can affect the effectiveness of the chlorine by dissolving it too quickly, before it has a chance to rid the pool of contaminants and clean the water.
To eliminate a green algae bloom, the recommendation is to breakpoint chlorinate to 30 ppm. Adding less than the breakpoint dosage can create more combined chlorine, exacerbating the problem.
Answer: After shocking the pool, it will need filtration and circulation. Run the pump as much as possible. Keep the filter clean (daily) until the water runs clear. Be sure to brush the pool often during this process as above-ground pools do not have drains at the bottom.