Step 1: work out the volume in litres
For a rectangular pool: length (m) × width (m) × average depth (m) × 1,000 = volume in litres. Average depth is the shallow-end depth plus the deep-end depth, divided by two.
Example: a 10 m × 5 m pool averaging 1.4 m deep holds 10 × 5 × 1.4 × 1,000 = 70,000 litres. For a round pool use 3.14 × radius × radius × average depth × 1,000.
Step 2: scale the dose to your pool
Chemtex dosing is quoted per 1,00,000 litres (1 lakh) or per 50,000 litres. Divide your volume by the base volume and multiply the dose.
| Product | Base dose | For a 70,000 L pool |
|---|---|---|
| Pool Chlor TCCA 90 | 1–1.5 kg per 1,00,000 L, at least once a fortnight | 0.7–1.05 kg |
| Pool Cide algaecide | 1 L per 1,00,000 L, once or twice weekly | 0.7 L |
| Pool Clear clarifier | 1 L per 1,00,000 L | 0.7 L |
| Pool Drop pH reducer | Per 50,000 L: 400 ml (pH 7.6–7.8), 500 ml (pH 7.8–8.0), 800 ml (above 8.0) | 560 ml, 700 ml or 1.12 L |
| Pool Build alkalinity increaser | Per 50,000 L: 450 ml (pH 7.0–7.2), 575 ml (pH 6.8–7.0), 700 ml (pH 6.5–6.7) | 630 ml, 805 ml or 980 ml |
For a small 10,000-litre pool, a 50,000-litre dose divided by five is the right amount.
Step 3: test before you dose
Use a pool test kit or strips to read pH and chlorine first. Dosing without testing is how pools end up over-corrected. The target band for pH is 7.2–7.6. Our guide to fixing high or low pH covers the correction step by step.
Tips for accurate dosing
- Measure depth at the shallow and deep ends, not from the pool's rated depth.
- Round volume down slightly if unsure; you can always add a second small dose, but you cannot remove an overdose.
- Dose along the pool edges with the filtration running, and re-test after the waiting period on each product page.
- Write the volume on the pump-room wall so every operator uses the same number.
Common questions
How do I calculate the volume of a swimming pool in litres?
Multiply length in metres by width in metres by average depth in metres, then by 1,000. A 10 m by 5 m pool averaging 1.4 m deep holds 70,000 litres.
What is the average depth of a pool with a shallow and a deep end?
Add the shallow-end depth and the deep-end depth and divide by two. A pool that is 1 m at one end and 1.8 m at the other averages 1.4 m.
How much chlorine do I need for a 70,000 litre pool?
Chemtex Pool Chlor TCCA 90 is dosed at 1 to 1.5 kg per 1,00,000 litres at least once a fortnight, so a 70,000 litre pool needs about 0.7 to 1.05 kg per dose.
Can I use the same dose for a smaller pool?
No. Scale the dose to the pool's volume. A 10,000 litre pool needs one-tenth of the 1,00,000 litre dose, or one-fifth of the 50,000 litre dose.
Products used in this guide
Need help with dosing for a hotel, club or society pool? Call +91-90739-38217 or contact us. Delivery across India, dispatched within 24 working hours.