Shocking Your Pool
Your swimming pool is meant to have clear and sparkling water. But have you ever thought that your swimming pool water ‘just doesn’t look right?’ It might be time to ‘shock’ your swimming pool! This process refers to adding chlorine (or non-chlorine) pool chemicals into the swimming pool in order to raise the “free chlorine” level. The goal is to raise this level to a point where contaminants such as algae, chloramines and bacteria are destroyed, roughly 10 times the combined chlorine level. Additional chemicals to ‘shock’ the pool back to clarity!
What You Need To Know!
What Do I Need To Shock My Pool?
You can regularly shock your pool as part of your general maintenance program, or if you are noticing algae beginning to grow in your pool/or a mustard colour on the side of your pool edge. Other reasons why you need to shock your pool is if the free chlorine level of your pool measures zero, or the chloramines or combined chlorine level rises above 0.5 parts per million (ppm). Leaving the water unchecked means algae growth could cause allergic reactions and even equipment damage to the pool pump and filtration systems.
How Often Should I Shock My Pool?
The more often you use your swimming pool, the more often you will need to shock it. Don’t wait for eye irritation or a bad smell before you shock your pool. Some recommend that you should do a pool shock once a week. You should also shock your swimming pool after heavy pool use, like a pool party. Also if there has been a severe rainstorm, or major water level change, and especially if there has been faeces in the pool.
How To Shock My Pool?
The best time to ’Shock’ your pool is at dusk. The sun can burn off unstabilised chlorine. Shocking your pool at night will make sure the chemicals can work properly. Also keep in mind that you will not be able to swim for 24 hours, as the strong chemicals could harm the skin.
Firstly it is worth testing the water to confirm it is worth shocking your pool. As well as physically checking the colour, using the strip, liquid or digital readers to get a good understanding of where your pool is at. Did you know that the darker the algae, the more infestation has occurred. There are three levels: light green algae, dark green algae, black green algae. The darker the algae, the more chemicals you will need to ‘shock’ the swimming pool.
Make sure you know the litres/gallons of your pool so you can get the right amount of ‘shock’ based on the water volume. All manufacturers are different, but as an estimation, if we were to use regular pool chlorine with 60% chlorine purposes, we would roughly need 100g of chlorine for every 10,000L of pool water for shocking purposes. With that as a baseline, we can get a rough idea of how much we’ll need to shock the pool. If you feel unsure speak to a professional for advice, please give us a call, we would be happy to help.
- Dissolve the granular chlorine shock in a bucket of water
- Make sure the pump is running (before, during and after you add the shock to the water)
- Pour the dissolved shock directly into the water, around the edges of the pool- ideally near a return jet
- If there are granules left in the bucket, dunk the bucket into the water near a jet to ‘blow out’ the rest of the solution into the water to dilute
- Using a pool brush, brush up any undissolved ‘shock’ that settles on the floor of the pool, to avoid any discoloration or staining on the pool surface.
- You will also need to clean your cartridge filter or backwash your sand filter and ensure your skimmer baskets and pump baskets are empty.
- Let the pump run for about six hours or more
- Test and rebalance the water to ensure proper chlorine levels for 2-3 days afterwards
- Switch the filtration system back to normal operational procedure
- Remember to allow 8- 24 hours before swimming (wait for the free chlorine levels to drop to 1 to 3 ppm)
- Make sure you wear gloves and safety glasses while working with pool chemicals
- Store the ‘shock’ granules in a dry and safe place, keeping in mind it is extremely combustible, so keep away from flames.
What About If I Have A Saltwater Pool?
Because saltwater pools use regular table salt to create chlorine (by passing the slightly salty water over two electrically charged plates), saltwater pools need to be shocked often, the same as your standard chlorinated swimming pool.
How often you need to shock a saltwater pool is the same as when to shock the chlorine pools. Either as part of your general maintenance program, or if you notice algae beginning to grow in your pool. Also if the free chlorine level of your pool measures zero, or the chloramines or combined chlorine level rises above 0.5 parts per million (ppm).
Granular pool shock, such as calcium hypochlorite, can also be used in a saltwater pool. You can follow the basic steps above for shocking a chlorine pool, as it is the same with how to shock a saltwater swimming pool.
A Quick Summary
Pool shocking is adding chlorine (or non-chlorine) pool chemicals into the swimming pool in order to raise the "free chlorine” level. The goal is to raise this level to a point where contaminants such as algae, chloramines and bacteria are destroyed.
Standard practice recommends you should shock your pool once per week. You should also shock your swimming pool after heavy pool use, like a pool party. or if there was a severe rainstorm, or major water level change, and especially if there has been faeces in the pool.
As a baseline, if you were to use regular chlorine you would want roughly 100g of chlorine for every 10,000 litres of pool water. Although it is recommended you speak with an expert to get a better idea for your pool.