Question 1

Why calculate water volume?

Accepted Answer

Pool chemistry — chlorine and pH adjusters — is dosed per litre. Pumps are sized by volume (aim to turn the water over 2–4 times a day). Heating depends on it: water's heat capacity is 4,186 J/(kg·K), so warming 1,000 L by 1°C needs 4,186 kJ.

Question 2

How much does pool water weigh?

Accepted Answer

One litre of water weighs 1 kg, so 9,000 L is 9 tonnes. A 10 × 5 × 1.5 m pool holds 75,000 L = 75 tonnes. That matters for floor loading: a typical limit is 150–200 kg/m², and 75 tonnes over 50 m² is 1,500 kg/m² — only safe on the ground or a dedicated foundation.

Question 3

How do I find the volume of an irregular pond?

Accepted Answer

Measure the water-surface area (e.g. from a photo) and multiply by the average depth. Average depth = the sum of soundings at several points divided by the number of points. The 10–20% error is fine for chemical dosing.

Question 4

How do I size a pool pump?

Accepted Answer

Pump flow (m³/h) = Volume / 4–8 hours (2–4 turnovers). A 30 m³ pool needs 30 / 6 ≈ 5 m³/h. Add a 20–30% margin and allow for pipe friction (about +20% per 10 m of Ø50 mm pipe at 2 m/s).

Question 5

How much chlorine does a pool need?

Accepted Answer

Target 0.5–1.0 mg/L (ppm) of free chlorine. For 9,000 L at 0.5 mg/L that is 4.5 g of active chlorine; as 56% dichlor granules, about 4.5 / 0.56 ≈ 8 g. Test 30 minutes after dosing, and keep pH at 7.2–7.6.

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