You might have just installed a swimming pool, moved into a rental property with a pool or purchased a new property with a swimming pool. Either way, now you need to know how to maintain it. One important pool maintenance requirement is to shock your pool. But how do you do that and what does shocking your pool even mean? In this article, we’ll find out how to shock a pool for beginners.
How To Shock A Pool in 6 Steps
1. Put on Your Safety Equipment
You’ll need adequate protection for your eyes and body, working with strong chemicals can be dangerous. Protective goggles and old clothes will come in handy here.
2. Test your pool water.
You’re looking for results for Free Chlorine and Total Chlorine. Write them down to help you calculate your shock treatment dose. Subtract your Free Chlorine from Total Chlorine to give you your Combined Chlorine.
3. Choose your shock treatment.
Most treatments are chlorine-based but there are alternatives. We have listed the shock treatments below.
4. Add the Shock to the pool.
Following the manufacturer’s instructions, measure the correct shock treatment dose. You will need to know the volume of pool water as well as your water testing results above to administer the correct dose. Many treatments will require you to mix up the treatment with water in a bucket first.
Treatment is usually added at dusk to ensure it can work without being used up by the sun’s UV rays.
Some pool owners have accidently added too much shock, don’t worry too much if you do though. We have a detailed article on this here:
Can You Over Shock Pool? Pool Now Green or Cloudy
5. Allow the treatment to work overnight.
Do not use the pool for approximately 8 hours while treatment is in progress.
Keep the pump running for 8 hours or more during shock treatment to mix the treatment throughout the swimming pool and ensure adequate filtration.
6. Test and Rebalance Pool
After the shock treatment, the following day, test your water and adjust the chemical levels as required.
You can read more on how to test your pool water here.
What Is Shocking A Pool?
Shocking a pool is the term given to using a heavy dose of chlorine, or other chemicals, to kill bacteria, algae, and chloramines from building up and becoming harmful. Another term for shocking your pool is known as super chlorinating.
Shocking your pool raises the free chlorine in the pool for a short time. This process is what kills the algae, bacteria and combined chlorine which is otherwise known as chloramines, a byproduct of chlorine.
It’s chloramines that create that strong chlorine smell which is a sign of pool water that is not correctly treated. Chloramines form when chlorine is doing its job and mixes with body fluids (think sweat and ugh, urine), sunscreen and heavy debris.
By shocking your swimming pool you keep your pool water healthy and clean, making it safe to swim.
Do I Need To Shock My Pool?
Yes, you do. And once you get the hang of it, shocking your pool will become a simple part of your pool maintenance routine. If you didn’t shock your pool, chloramines would build up creating a breeding ground of bacteria, algae and other nasties in the water that could make you sick.
How Often Should You Shock Your Pool?
During a normal swimming season, it’s recommended you shock your pool about once a week. This will ensure clean and safe water for daily pool use. However, heavy use, of say a pool party or heavy rain may warrant further treatment.
Know The Right Time Of Day To Shock A Pool
In most cases, you should shock your pool at dusk or the evening. This is so the sun’s UV rays do not destroy the shock treatment before it has a chance to do its job.
How Long After Shocking a Pool Before Is It Safe For Swimming
Generally, you should not swim in a pool for 8 hours following shock treatment. Be guided by your shock treatment of choice and follow the manufacturer’s instructions.
If you use a non-chlorinated treatment the time can be as little as 15 minutes, however, these types of treatments will not work against algae bloom.
Types of Shock Treatment
This is the most common form of shock treatment. It’s widely available and inexpensive. More importantly, it’s effective.
Use this treatment at dusk or night as sunlight will use it up before it has done the job.
This treatment usually requires mixing it up in water to dissolve the granules before adding to the pool water.
We recommend this Calcium Hypochlorite Shock Treatment.
This is again a granular powder that requires mixing up in a bucket of water before adding to the pool.
It is a longer-lasting treatment however because it contains cyanuric acid which is a pool water stabiliser. Over time the cyanuric acid level will rise.
Again, use this treatment at dusk or the evening to ensure less sunlight exposure.
We recommend this Sodium Dichlor Shock Treatment.
If calcium levels are high, this might be a good option as it does not contain calcium. Use a water testing kit to determine this. It’s often a liquid treatment so you won’t have to mix it in water.
If time is an issue and you can’t wait for the normal 8 hours to swim, you could use a non-chlorine treatment.
They usually only require 15 minutes of not swimming in the water. These treatments contain potassium peroxymonosulfate and do not work on killing algae.
So there are pros and cons to using this product. If you suspect an algae problem you should use another product.
We recommend this Non-Chlorine Shock Treatment.
Shocking your pool is easy once you learn how. After the first couple of treatments, it will become part of your routine in no time at all. By practising great pool maintenance you’ll always know you have a safe and clean pool for swimming.
Shock Treatment – most common treatment Calcium Hypochlorite
Sodium Dichlor Shock Treatment – Longer lasting treatment
Non-Chlorine Shock Treatment – for treatment without chlorine
Do you want to reduce your pool cleaning time? Read our guide How To Clean A Pool: A Time Saving Guide.
Related Reading: Do You Need to Shock Hot Tubs?