Everything You Need to Know About Chlorine In Your Above Ground Pool


How Does Shock Dosing Work?

Shocking your Above Ground Pool water refers to adding large quantities of chemicals (maybe 5-10 times the normal dose) in order to break down any organic waste and contamination and re-establish a positive level of sanitisation. 

When Do I Need to Shock My Above Ground Pool Water?

Your Above Ground Pool water should be shocked when:
  • You first fill up your Above Ground Pool
  • At the first signs of algae or slime
  • After periods of heavy usage
  • After a loss of water clarity or quality

How Often Should I Shock My Above Ground Pool Water?

It is good practise to shock treat the pool water after a period of high usage. This will help to rectify the sanitizer level, prevent the growth of microorganisms and help maintain sparkling, crystal clear water. After treatment, water quality and clarity is often completely restored. 

We know that chemicals are a pretty confusing part of owning an above ground pool, so we have made it super easy for you with shock dosages depending on your Above Ground Pool size and answers to some FAQs.

Above Ground Pool Clearwater Shock Dosing Rates:

Please note:

This guide is only applicable to Clearwater Chemicals. If you are using other chemicals, dosages may vary. 
Dosages are only approximate depending on exact amount of water in your pool, pool size, local water type, water temperature, positioning of pool, weather, bather load etc.

To find out the water volume of your pool visit here.

Pool Size  Water Volume (Litres) Approx. shock 
dose Chlorine amount.
daily Chlorine amount.

3,408L 38g 10g
8ft x 3ft 4,545L 50g 13g

5.680L 63g 16g
10ft x 3ft 6,816L 75g 20g
7,952L 88g 23g
12ft x 3ft 9,090L 100g 26g

10,224L 113g 29g

11,360L 125g 33g
12ft x 4ft 12,496L 138g 36g

13,632L 150g 39g
15ft x 4ft 20,430L 225g 59g

After shock treating your Above Ground Pool water, wait a minimum of 1-2 hours after chemical additions (with circulation running) before bathing.

WARNING: You must always test your water before use using Clearwater Dip Test Strips. Water must be at recommended bathing level (1-3ppm for pools) before bathing. 

Shock Dosing FAQs

I purchased large 200g Chlorine Tablets for my Lay-Z-Spa. How do I use these?

These big tablets are designed for 15ft + swimming pools. The water treatment tablets should be used with a Bestway 6.5 Inch Chemical Floater, which slowly releases them into a pool to keep it consistently clean.

As well as containing chlorine, which kills bacteria and other potentially harmful organisms by disinfecting water, the tablets also contain an algaecide solution and water clarifier that contains flocculants, which bind particles together so that a pool filter can trap them with ease, producing a clean and healthy swimming environment. 

I have added an initial dose of Stabilised Chlorine to my pool, when can I use it?

The pool can be used when the chlorine level has dropped to 1-3mg/l (ppm) or below. This may take some time.

I have added an initial dose of Stabilised Chlorine to my pool. I am getting strange pH & Total Alkalinity readings?

The chlorine level is still probably very high which can give inaccurate pH & TA readings. Wait for the chlorine level to drop to 1-3mg/l (ppm), then re-test pH & TA and if necessary adjust.

There isn’t a measuring scoop in the chemical container. How do I measure out the quantity I need?

A level teaspoon holds approx. 5g of dry product. Never use the same teaspoon to measure different chemicals without
cleaning thoroughly first.

I need to buy more chemicals, where can I purchase them from?

You can purchase further supplies from here.

Why am I not getting a chlorine reading on my test strips?

Have you added any chlorine recently? 

Yes, an initial dose for my pool – The chlorine level may still be high leading to
bleaching of the test strip pads. Leave for a few hours and re-test.

No, I added chlorine a couple of days ago. Chlorine gets used even if the
pool isn’t being used. Dose Stabilised Chlorine Granules daily.