Shocking your pool is the process of super-chlorinating your pool to keep it clean. This eliminates any algae, bacteria, and other harmful pathogens in the water, ensuring that it’s safe to swim in. You can shock your pool on your own, but to make sure that you do it right, it’s important to understand the basics, including how to shock a pool, how often to shock a pool, and how much shock to add to a pool.
Pool shocking is done by leaving chlorine or non-chlorine chemicals in the pool for a couple of hours, and it’s best to do it at least once a week. The amount of shock you need to use will depend on your pool’s volume and state, but for general maintenance, it usually takes a pound of shock for every 10,000 gallons of water.
How Does Shocking a Pool Work?
First thing first: what is shocking a pool? Pool shocking is another term for super-chlorination, which involves adding chemicals to pool water to sanitize the water and destroy any harmful bacteria and pathogens.
Shocking a pool is primarily done to deal with the amount of chlorine in the water. Chlorine is the top disinfectant for most pools. When it’s newly added, it acts as free chlorine (FC), actively cleaning the pool. But after some time, the used chlorine becomes combined chlorine (CC, also known as chloramines), which is less effective as it’s already mixed with other bacteria and chemicals in the pool, such as sweat and sunblock, or it has been diluted by the sun or extra water.
Shocking a pool releases chloramines and off-gasses pool contaminants, while increasing the level of FC.
Types of Pool Shock
There are many different chemicals that you can use to shock your pool. Here are the three most common ones:
Calcium Hypochlorite Shock
Cal-hypo shock is ideal if you need strong treatment to deal with a really dirty pool. That said, it contains calcium, so if you have a saltwater pool, use it sparingly since it can cause buildup in a salt generator. It’s also unstabilized chlorine, which means that the sun can make it weak. So, if you’re using cal-hypo shock, it’s best to shock your pool at night.
Sodium Dichlor Shock
Dichlor shock contains less chlorine than cal-hypo shock, so you can use it for weekly treatments or combat less severe algae issues. It contains cyanuric acid (CYA), which makes it a stabilized chlorine, so you can use it during the day. However, you still need to wait eight hours before you can swim after shocking your pool.
Non-chlorine shock, as the name suggests, is a chemical that contains no chlorine. It’s great for mild and frequent treatments, but since it’s more of an oxidizer than a sanitizer, it won’t be able to effectively treat severe algae problems.
How to Shock a Pool
Shocking a pool can be done in six simple steps:
Protect yourself with the necessary gear.
Determine how much shock to add and prepare it according to the manufacturer’s instructions.
Pour the pool shock into the water.
Leave the pool shock overnight (or at least eight hours).
Check the chemical levels of your pool.
Filter your pool for twenty-four hours to remove germs or algae.
To know more, check out Pool Care Guy’s helpful guide linked above.
Most shock treatments will have instructions on how much product to use every time you shock your pool. You should follow these as the strength and effectiveness of shock differs per product. That said, the instructions will only likely be a guide; you’ll still have to do some math to get the right numbers.
In general, weekly shock treatments will require a pound of shock for every 10,000 gallons of water. But you’ll need to double, triple, or quadruple this measurement depending on the volume of your pool and how grave your algae problem is.
If you need to know your pool’s volume, just check your blueprint or ask your pool company for the dimensions. You can also use a pool volume calculator online. To determine your pool’s algae state, you can typically categorize it based on the greenish-ness of the water: teal green for small or new algae growth, dark green for significant algae growth, and black green for hard-to-kill algae problems.
Get Help From the Pool Care Guy
Keeping your pool cool, clean, and clear requires some work, but it’s not at all complicated, and you don’t have to spend a lot just to maintain your oasis. Pool Care Guy can give you all the info and tips you need to look after your pool. Check out our helpful guides today!
Hi, I’m Matt Harper, the founder of poolcareguy.com, a site I started with one simple mission: to help people around the world clean and take care of their pools and hot tubs on their own, without the hassle.
I’m not a professional pool cleaner and don’t have any formal training, I’m just an average guy who loves hanging out by his pool and hot tub and taking care of it. After many years on the job, I’ve become quite good at it.
On this website I will be teaching you absolutely everything I know about pools and hot tubs.