Dosing

How many bags, and when they arrive.

Three inputs. The answer is given in bags, with the delivered total and the next run day for your zone.

1 · Pool

2 · Volume

Pool volume (litres)

3 · Current magnesium

Current level (ppm), if known

Leave at zero if you have not tested. Target is 450 ppm of elemental magnesium.

Result

bags of 10kg

2 bags · $115.95 delivered · First deliveries once our first shipment clears.

Delivery is $17.95 on this order. Add 2 more bags and delivery is free.

Reserve 2 bags

Keep it topped up

For a pool this size a Subscription of 3 bags every 6 months suits, which is 6 bags a year.

Most pools use two to five bags a year. Adjust the interval if yours differs — you can change it any time.

Set up a Subscription

The working

Volume45,000 L

Target450 ppm elemental Mg

Starting level400 ppm

Lift required50 ppm

Rate0.85 kg / 1,000 L / 100 ppm

Mineral required19.1 kg

Rounded to bags2 × 10kg

Indicative only. The 450 ppm target is a general industry figure for magnesium pool water, not a product-specific recommendation, and it holds total mineral salinity near 3,800 ppm. Your chlorinator manufacturer's stated operating range takes precedence over this calculator. Test your water before and after dosing. Check compatibility.