How much salt to put in a pool – calculation and table by volume
Short answer: How much salt is put in a pool depends on the salt electrolysis device. Usually, this is between 2,5 and 4,5 kg of salt per cubic meter of water (2,5–4,5 g/l), and for REGUL devices – about 4–5 g/l. For a 30 m³ pool at 4 g/l, 120 kg is needed, i.e. 5 bags of 25 kg.
How to calculate how much salt to put in a pool
The formula is simple: pool volume (m³) × concentration (g/l) = kilograms of salt. One gram per liter is the same as one kilogram per cubic meter. Calculate the volume by pool volume formulas. Take the concentration from your appliance manual.
Table: how much salt to put in a pool according to volume
| Pool volume | At 3 g/l | At 4 g/l |
|---|---|---|
| 10 m ³ | 30 kg (2 bags) | 40 kg (2 bags) |
| 20 m³ | 60 kg (3 bags) | 80 kg (4 bags) |
| 30 m ³ | 90 kg (4 bags) | 120 kg (5 bags) |
| 40 m³ | 120 kg (5 bags) | 160 kg (7 bags) |
| 50 m ³ | 150 kg (6 bags) | 200 kg (8 bags) |
| 60 m ³ | 180 kg (8 bags) | 240 kg (10 bags) |
The bags are 25 kg, rounded up. Put a little less in the beginning: the salt is easy to add, and the excess is removed with just a partial water change.
How to add salt
- Calculate the quantity using the table or formula.
- Dissolve the salt in a separate container of water before pouring it into the pool.
- Pour it while the filtration is running so that it is distributed evenly.
- Turn on the electrolysis device after the salt has completely dissolved. Follow the device’s instructions.
- Measure the concentration with salt tester and add more if necessary.
How often is salt added to a pool?
The device does not use up salt: during electrolysis, it is converted into chlorine, and after disinfection back into salt. Salt is lost when washing the filter, when spraying and when rain dilutes the water. Therefore, it is only topped up when the measurement shows that the concentration has fallen below the device’s norm.
According to the salt tester, the optimal concentration is between 2000 and 6000 mg/l. Below 2000 mg/l, the salt generator works less well. Measure at least twice a week, and more often in warm water.
What salt to choose
Use salt intended for swimming pools: sea salt or technical salt, both in 25 kg bags. The devices that make chlorine from salt are in the category Salt electrolysis.
Frequently asked questions
How much salt is needed for a 30 m³ pool?
At 4 g/l, 120 kg are needed, i.e. 5 bags of 25 kg. At 3 g/l, 90 kg.
Can salt be too much?
Yes. The recommended range on the tester is 2000–6000 mg/l. Excess salt is removed only by partial water changes, so add in portions and measure.
Is the appliance running out of salt?
No. During electrolysis, salt is converted to chlorine, and after disinfection, back to salt. It is lost when the filter is washed, when spraying, and when rain dilutes the water.
Last content check: 30.09.2026
