Yesterday you had an amazing pool party that ran all afternoon and into the night. Your friends even complimented you on having such a sparkling clean pool. However, this morning when you checked the pool it smells like bleach and has lost its sparkle. Read this article to learn how to shock treatment your swimming pool back to good health.
When swimming pool water begins to emit a strong bleach smell or looks dull, hazy or pale green this indicates there is little or no free chlorine in the water. This commonly occurs after heavy usage, a period of hot weather or a storm which diminishes the free chlorine leaving your pool open to bacteria and a build-up of chloramines. Adding a shock treatment to your swimming pool will solve the problem.
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What is Shocking Your Pool?
The term “shocking your pool” is pool industry slang language for super chlorinating your pool. All it means is giving your pool an extra dose of chlorine to ensure the pool is adequately sanitized by killing bacteria, viruses and algae that may exist in the water.
Why Shock Treatment Your Swimming Pool?
Super chlorinating a pool is part of the normal maintenance routine. Shock will kill bacteria, algae and eliminate the build-up of chloramines in the water. Many pool owners fail to shock their pool on a regular basis running the risk of their pool turning green, cloudy or having unbalanced water that begins to damage pool surfaces and equipment.
What are Chloramines?
Chloramines are the chemical residue after chlorine has reacted and bound with dirt, sweat, sunscreen, urine, bird droppings, decaying insects, bacteria, algae and anything else that invades your pool water. If you pool water smells like bleach then you have too many chloramines in the water and it’s time to shock the water.
Chloramines build up in the water making it easier for bacteria and algae to multiply and take over the pool. Shocking the pool water (super chlorinating) eliminates chloramines and keeps your pool water sanitized.
Please read our Pool Chemistry Guide
When to Shock Treatment Your Swimming Pool
In the summer season when your pool is in constant use you must shock treatment the swimming pool every week or fortnight. In the off seasons when the pool is not being used once a month or every second month is sufficient to maintain free chlorine levels.
The best time of day to add shock to your pool is in the evening after you have finished using the pool for the day and just before the pump is due to operate.
Adding the shock after the sun has gone down will ensure it works all night as there is no ultraviolet light to reduce its effectiveness. Also it is cooler reducing chlorine evaporation from the water.
You must always circulate the water in the pool after adding shock so the best time to add is just before the pump comes on. Make sure the pump is going to run for at least 4 hours to thoroughly mix in the shock chemical. Do not swim in a pool straight after adding shock chemicals because the high free chlorine will sting your eyes and itch your skin.
Shock treatment your pool in the evening to guarantee it’s sanitized and fresh ready for swimming the next day.
Best Way to Shock Treatment Your Swimming Pool
Before you handle any chemicals make sure that you are using protective clothing and gloves. I recommend a mask and eye protection as well. Try not to add chemicals to your pool when there is a breeze as you might end up wearing the chemicals.
Most shock treatments are a powder or granular chemical that comes packaged in a one dose pack which is the correct size for the average backyard pool. Normally, you can spread the shock around over the pool surface. Carefully read the manufacturer’s instructions to ensure you are applying the shock correctly for your pool.
Test the water the next day to make sure the pool is still balanced and adjust levels as required.
Shock treatments can cause the pool water to look cloudy for a few days. This is normal and will dissipate over the next few days as the free chlorine reacts to other compounds in the pool.
After Shocking When is it Safe for Swimming?
Do not swim for at least 8 hours in your pool after adding shock. Give the shock chemical time to dissolve, mix into the water and perform its chemical reactions. Add the shock to the pool in the evening so you can swim in the pool the next morning.
Which Shock Treatment to Use?
The most widely used shock treatment is calcium hypochlorite.
If your calcium level is already high don’t use shock containing calcium hypochlorite as this will make it worse. Use lithium hypochlorite or sodium hypochlorite instead.
Some products can be directly added to the pool water. Others are best mixed into a bucket of water first. Always follow the instructions on the packet.
Safety and Handling
Pool chemicals are dangerous and reactive.
Please ensure that all pool chemicals are stored in a cool, dry location and kept out of the reach of children. Wear gloves and protective clothing when handling chemicals. Always carefully read the instructions on the packaging.
NEVER MIX CHEMICALS TOGETHER
You should never mix pool chemicals together as they may react leading to fire, explosion or release of toxic chlorine gas. Even mixing dry chlorine with liquid chlorine may cause an explosion.
NEVER ADD WATER TO CHEMICALS, ALWAYS ADD CHEMICALS TO WATER.
You must never add water to chemicals because the chemical may react with the water causing an explosion. Or it may release toxic chlorine gas that has the potential to damage your lungs. It is far safer to add a small amount of chemical to a larger amount of water to reduce any unwanted reactions.
How to Shock a Salt Water Pool
You need to frequently super chlorinate your saltwater swimming pool.
You need to frequently and manually add chlorine to a fresh water pool to ensure the pool water is sanitized from bacteria and algae. Normally, an automatic chlorine dispenser is used such as a floating tablet holder. The chlorine tablet slowly dissolves into the water providing adequate free chlorine to the pool.
A salt water pool has pool salt, which is sodium chloride, dissolved into the water. The level of salinity is very weak. It’s nowhere near as salty as seawater so it’s very safe for people to swim in. The free chlorine is generated by running the pool water through a chlorinator cell after the filter unit. The chlorinator cell operates with an electrical current over an anode and cathode to chemically split the chlorine from the salt. Effectively, a salt water pool is a chlorinated pool. It has the same amount of free chlorine in the water as a chlorinated fresh water pool.
Turn up and down the salt water chlorinator to produce the desired level of chlorine for your pool. However, turning up the chlorinator and/or running the pump longer still doesn’t usually generate enough chlorine to shock the pool. So you need to add shock to a salt water pool as you would a fresh water pool.
As mentioned above you need to shock the pool every week or fortnight in the summer season and less frequently when not using the pool. When you have shocked your pool you can reduce the chlorine production from the chlorinator for a day or two. Producing too much chlorine will not have any extra benefit.
How to Prepare your Pool for a Party
If you are planning a pool party or your kids are bringing over their friends to swim in the pool tomorrow what can you do to ensure the pool water will stay sanitized?
Firstly, you may want to turn up the chlorinator unit to generate more free chlorine for the next couple of days. This will ensure your free chlorine level will be adequate to sanitize the water for the extra usage.
You could run the pump for an extra hour before and after the party. This will also generate extra free chlorine to keep the pool sanitized for a longer period. It will also filter out the dirt and debris left by swimmers.
But the best method is to shock your pool after the party. This will eliminate all the sweat, sunscreen, urine, dirt and everything else that uses up the free chlorine in the water. Add shock treatment to the pool straight after the party has ended with the pump running into the night. The next day you have a fresh, clean pool ready for use again.
Conclusion
Frequently shocking your pool with a chlorinated product must be part of your maintenance routine. This ensures you have a safe, clean pool for your family and friends to enjoy throughout the summer.
Check out our other posts on this site to help you better manage your pool maintenance. These posts will help reduce the time and effort to operate your pool. After all, you want to spend more time in your pool rather than maintaining it.
