The right amount of chlorine depends on two things: how many litres your pool holds, and which chlorine product you use. The goal is the same for every pool: keep free chlorine between 1 and 3 ppm, with pH between 7.2 and 7.6.
Quick answer: with Chloro Maxx 90 tablets, the regular dose is 300 to 350 g per 1 lakh litres of water. A 50,000 litre pool needs 150 to 175 g. For your exact pool size, use our pool dose calculator.
Step 1: Work out how many litres your pool holds
Multiply length × width × average depth.
- In feet: length × width × average depth × 28.3 = litres. A 30 ft × 15 ft pool, 4.5 ft deep on average, holds about 57,000 litres.
- In metres: length × width × average depth × 1,000 = litres. A 10 m × 5 m pool, 1.4 m deep on average, holds about 70,000 litres.
For the average depth, add the shallow-end and deep-end depths and divide by 2.
Step 2: Chlorine dose chart by pool size
All doses are from the Pool Maxx product labels.
| Pool size | Chloro Maxx 90 Tablets, regular dose | Tablets, shock dose | Chloro Maxx 90 Granules, to raise 1 ppm | Hypo Pool Shock, shock dose |
|---|---|---|---|---|
| 20,000 litres | 60 to 70 g | 110 to 220 g | 30 g | 150 to 240 g |
| 30,000 litres | 90 to 105 g | 165 to 330 g | 45 g | 225 to 360 g |
| 50,000 litres | 150 to 175 g | 275 to 550 g | 75 g | 375 to 600 g |
| 75,000 litres | 225 to 265 g | 415 to 825 g | 115 g | 565 to 900 g |
| 1,00,000 litres | 300 to 350 g | 550 g to 1.1 kg | 150 g | 750 g to 1.2 kg |
Which chlorine should you use?
Chloro Maxx 90 Tablets: for everyday chlorination
Chloro Maxx 90 Tablets dissolve slowly, so they keep chlorine steady. The regular dose of 300 to 350 g per 1 lakh litres gives 3 to 5 ppm. Put them in the skimmer, a floater or a tablet feeder with the pump running. Stay out of the pool for 4 to 6 hours after dosing.
Chloro Maxx 90 Granules: to top up quickly
Chloro Maxx 90 Granules raise chlorine fast. 75 g per 50,000 litres raises free chlorine by 1 ppm. Dissolve the granules in 10 litres of clean water first, then add to the pool with the water circulating. Re-check after 24 hours.
Hypo Pool Shock: for a strong shock
Hypo Pool Shock is for cloudy or green water, after rain or heavy use, or a weekly shock. 150 g per 1 lakh litres raises chlorine by 1 ppm; a shock is 5 to 8 times that. Dissolve it in a bucket first, run the filter 8 to 10 hours, and stay out for 4 to 6 hours.
When to shock instead of the regular dose
- Every 7 days in a busy pool.
- After a party or heavy use.
- After heavy rain.
- When you see algae or the water turns green. See how to fix a green pool.
After a tablet shock (550 to 1,100 g per 1 lakh litres), do not swim until free chlorine drops below 4 ppm, and re-check after 24 hours.
Why pH matters as much as chlorine
Chlorine works best at pH 7.2 to 7.6. If pH is too high, you can add plenty of chlorine and still get cloudy or green water. Test pH first, and correct it with pH Down or pH Up before adding chlorine. Never add more than half the pH dose at once.
Prefer no chlorine at all?
Pool Maxx 35 is a chlorine-free sanitiser: 1 litre per 1 lakh litres every 24 to 48 hours, with pH at 6.5 to 7.0. Do not use it with chlorine. Stop chlorine 24 hours before switching, and the chlorine level should read zero.
Common questions
How often should I test chlorine?
At least twice a week, and after rain or heavy use. Pool Maxx 5-in-1 test strips read free chlorine, total chlorine, pH, alkalinity and hardness in one dip.
How much chlorine for a 1 lakh litre pool?
With Chloro Maxx 90 tablets, 300 to 350 g as a regular dose, and 550 g to 1.1 kg as a shock.
Can I swim right after adding chlorine?
No. After a regular tablet dose, wait 4 to 6 hours. After a shock, wait until free chlorine is below 4 ppm.
Get chlorine, pH balancers and clarifier together in the Starter Pool Care Kit, or ask our team about bulk supply for hotels, clubs and housing societies.
