How to Use Shock Chlorine Tablets

Swimming pools should be shock chlorinated at least once a week, more frequently if your area has had heavy rains or long stretches of direct sunlight. The addition of 65 percent Calcium Hypochlorite (granular form) or 99 percent Trichloro-S-Triazinetrione (tablet form) will combine with harmful bacteria and other microorganisms to neutralize them. Regular chlorination of the pool can be tied up by the bacteria and become inactive. This is called combined chlorine. The combined chlorine must be removed in order to establish healthy water for human usage. Shocking the water overcomes the combined chlorine and destroys harmful bacteria.

Difficulty: Moderate

Instructions

Things You'll Need:

• 3 inch pool chlorine tablets - 99 percent Trichloro-S-Triazinetrione
• 5-gallon bucket
• 1 packet of 65 percent Calcium Hypochlorite
• Long wooden stick

Tablets

1. Test the pool water before any shock treatment is performed (see Resources).

2. Adjust the Ph level in the pool to between 7.2 and 7.6. The water must be stabilized for proper Ph or the chlorine will not be effective.

3. Turn on the pool's circulation pump. Add two tablets per 6,500 gallons of pool water into the pump's intake at the skimmer basket.

4. Allow the tablets to dissolve. Test the water for chlorination levels.

Granules

5. Fill the bucket three-quarters full with pool water. Add the granules to the water. Never add water to dry chemicals; always pour the dry chemicals into the water.

6. Stir the chemical well with a long wooden stick for at least one full minute or until all visible granules are dissolved. Turn on the pool's circulation pump.

7. Pour three-quarters of the chlorine solution slowly into the pool in front of the pool's pump suction intake. You should be able to see the solution exiting the pump's outlet vents in the pool. Leave one-quarter of the solution in the bucket. There will be undissolved granules remaining.

8. Add more water to the bucket and stir the undissolved granules for another minute or until it is fully dissolved.

9. Pour the remaining solution into the pool, again in front of the pool's pump intake. Follow the chemical's manufacturer's recommendations before entering the pool.

Tips & Warnings

• Granular shocking is a little more work, but the chlorine reaction time will be faster. Follow the University of Georgia Resource link for shock chlorination of private wells and cisterns.
• Store-bought bleach will not shock a pool because the concentration of Calcium Hypochlorite is not strong enough.

References

• Swimming Pool Shocking Tablets
• Swimming Pool Shocking Granules

Resources

• Pool Testing
• University of Georgia