How much chlorine should be in my pool?

Amount of chlorine in the pool

Proper chlorine levels in your pool are very important. It keeps your pool healthy and removes bacteria from your pool. But how much chlorine should you add and how often?


First of all, it is important to know how much chlorine should be in your pool. For outdoor pools, a chlorine level between 0.5 and 3 ppm is good. For indoor pools, chlorine levels should be between 0.5 and 1.5 ppm. For spas, then again, between 1 and 3 ppm is the perfect level. PPM is short for Parts Per Million, which translates to 1 mg per litre of pool water (0.001g/l). 

Always make sure the pH level is between 7.2 and 7.6 first, otherwise the chlorine will not work. Measuring pH and chlorine levels can be done with test strips, test kits or a digital meter.

How often should I measure and add my chlorine?

It is important to first know how much chlorine is in your pool. Have you just refilled, has it just been winter or has there been a heavy downpour? Then first add a chlorine shock tablet, which will boost the chlorine level. 

If you don't use your pool often, it's enough to measure your pH and chlorine once a week. If you use the pool a lot, it's best to do this 2 - 3 times a week. 

Adding chlorine to the water should be done regularly. If the weather is cold and the pool is not used a lot this can be done every 2 weeks. However, if the weather is warm and the pool is used a lot, adding a dose of chlorine granules or a chlorine tablet every week is fine.

Lovibond tester

pH and chlorine testers

Scuba II Lovibond Electronic tester
Top seller
Scuba II Lovibond Electronic tester
115,00 €
  • Electronic tester for water quality
  • Measures chlorine, pH value, alkalinity and cyanuric acid
  • Contains test tablets en 2 AAA batteries
  • Best price / quality
Electronic tester for water quality
AquaChek TruTest digital water tester
Digital tester water quality
89,95 €
  • Digital tester to check the water quality
  • To analyse Chlorine, pH and Alkalinity
  • 25 test strips included
  • Power source: 2 x AA penlite battery (not included)
Digital tester for chlorine, pH and alkalinity
Blue Connect Plus - Salt
Blue by Riiot intelligent water tester
429,01 €
  • Intelligent analysis device
  • Gives step-by-step plan to improve the quality
  • Measures pH, chlorine, temperature and conductivity
  • Also for salt electrolysis
The ultimate intelligent analysis device

How much chlorine should I add?

This depends on the status of your pool. As told above, is it just coming out of winter or have you just filled it? Then it's best to do a chlorine shock. For a chlorine shock, it is best to add 120 grams of granules per 10 m3. 

If you want to give the pool a regular maintenance dose, you should add 40 grams of granules per 10m3. Of course, you can also work with chlorine tablets, which is more convenient for slightly larger pools. With chlorine tablets, you can count on 1 tablet (200g) per 30m3.

Type of treatment

Type of chlorine



30 m3 

40 m3 

50 m3 

60 m3 

Chlorine shock 

Chlorine granulate 

120 g 

240 g 

360 g 

480 g 

600 g 

720 g 

Normal maintenance 

Chlorine granulate 

40 g 

80 g 

120 g 

160 g 

200 g 

240 g 


Chlorine tablet (200g) 




Which chlorine is best for my pool?

There are 3 different types of chlorine. Chlorine granules, chlorine tablets and liquid chlorine. Liquid chlorine is not suitable for most pools, this is especially for public pools with an automatic dosing system. 

The other 2 types of chlorine are chlorine granules and chlorine tablets. Chlorine granules are the most accessible as they can be used for chlorine shock and normal maintenance and the amount can be adjusted to the size of the pool. 

Chlorine tablets, in turn, are more convenient, you can just put them in the skimmer and they do their job. They come in 200g tablets, making them optimal for pools from 30 m3.

Eur-o-Choc chlorine granules 5 kg
Top seller
Chlorine granules
33,50 €
  • To quickly correct the chlorine
  • Ideal for shock treatment
  • Contents 5kg
  • Only for private swimming pools
Chlorine granules
Chlorine tablets 10 kg
Chlorine tablets 10 kg
69,00 €
  • Affordable price
  • For continuous water purification
  • Weight per tablet: 200 grams
  • Contents = 10kg
Chlorine tablets 10 kg
Liquid Chlorine BE-REG-00358 20 L (Chloorbleekloog)
Top seller
Liquid Chlorine BE-REG-00358 20 L (Chloorbleekloog)
27,00 €
  • Liquid chlorine
  • Used for shock chlorination
  • Mostly used for automated dosing
  • Contents 20L
  • Disposable packaging
Liquid chlorine

Keep an eye on it

So make sure you measure the pH and chlorine regularly so that it does not become too much or too little. Too little chlorine allows algae and bacteria to spread better. With too much chlorine, you may suffer from red eyes or itchy skin after swimming.