What is Pool Shock? The Different Types of Pool Shocks Explained
Owning a pool comes with the responsibility of keeping it clean and safe for swimmers. One essential aspect of pool maintenance is shock treatment, a process that involves adding a high concentration of chemicals to the water to eliminate bacteria, algae, and other contaminants, as well as to break up chloramines (spent/useless chlorine). However, with various types of pool shock available, choosing the right one can be confusing. Our Pool Pros have written a guide where we'll explore the differences between the three common types of pool shock: calcium hypochlorite shock, di-chlor shock, and oxidizing shock.
Both calcium hypochlorite shock, otherwise known as super shock, and di-chlor shock are known as chlorine shocks. We recommend using one of these shocks once every 7 days or after heavy use. But, which shock should you use?
What is Calcium Hypochlorite Shock?
Calcium hypochlorite shock, known as cal-hypo or super shock, is a quick-dissolving shock and one of the main shocks you should use for your primary shock treatment. Typically available in granular form, it effectively kills bacteria, algae, and other harmful contaminants. It also boosts your chlorine level, helping to keep the water clean and safe for swimming. If you have an unexpected algae bloom, this shock will help to clear your pool.
Cal-hypo shock is great for spring start-up as well as it has a high oxidizing power. While being the most popular type of shock, it's essential to note that calcium hypochlorite shock can raise the pH level of the pool water. Therefore, regular monitoring and adjustment of pH levels are necessary after its use.
Doheny’s Pro-Grade Super Pool Shock contains 68% active ingredient calcium hypochlorite, 65% available chlorine, and is used to sanitize and help clear even the most contaminated pools.
What is Di-Chlor Shock?
Di-chlor shock is a stabilized form of granular chlorine, containing chlorine and cyanuric acid. While it has a moderate oxidizing power, it is effective at killing bacteria and algae. Unlike calcium hypochlorite shock, di-chlor shock tends to lower the pH level of the pool water. Pool owners should be prepared to adjust pH levels accordingly after its application. It can act as a 3-in-1 concentrate treatment used as both a primary sanitizer as well as a shock treatment.
Since di-chlor shock is a little less “harsh” than cal-hypo shock, it’s great for use in vinyl-liner pools and other more sensitive pool environments. It’s extremely compatible with salt and liquid-treated pools as well. Since it’s stabilized, it’s protected from the sun’s UV ray “burn off”.
Doheny's Pro-Grade Di-Chlor Chlorinating Shock contains 99% active ingredient Sodium Dichloro-S-Triazinetrione and 56% available chlorine.
What is Non-Chlorine or “Oxidizing” Shock?
Oxidizing shock, often containing potassium monopersulfate, provides an alternative to chlorine-based shocks. It’s mainly used to burn off dead or “spent” chlorine cells and helps to boost the active chlorine cells in your pool. One significant advantage of oxidizing shock is its minimal impact on the pH level of the pool water. It's a suitable choice for pool owners concerned about chlorine sensitivity or looking for a chlorine-neutral shock treatment.
Oxidizing shock is the least “harsh” of the shocks, making it safe for all pool surfaces. Swimmers are able to return to the water after just 15 minutes of application! It will not burn the eyes or cause skin irritation. We recommend using oxidizing shock once a week alongside (though not on the same day as) a chlorine shock to ensure your pool is safe and crystal clear throughout the pool season.
Doheny's Pro-Grade Oxidizing Shock contains 42% active ingredient Potassium Monopersulfate. Ensure the best results when used in tandem with either Doheny’s Super Shock or Doheny’s Di-Chlor Shock.
In conclusion, choosing the right pool shock depends on various factors, including the level of contamination, pH balance, cyanuric acid levels, and the chlorine sensitivity of the pool. Calcium hypochlorite shock offers potent oxidizing power but raises pH, di-chlor shock is stabilized but lowers pH, while oxidizing shock is chlorine-neutral and suitable for maintaining chlorine levels without affecting pH. By understanding the differences between these types of pool shock, pool owners can make informed decisions to keep their pools clean and safe for enjoyment all season long.
To learn more about using shock, check out our blog on how to shock your pool.
