Product Details

Brand: PTL Direct

Protect your spa, above ground, or inground pool from corrosion, foaming, and surface damage with Calcium Hardness Increaser. This fast-dissolving, fully soluble formula safely raises calcium hardness levels, helping prevent etching, scaling, and wear on heaters, pumps, liners, and pool finishes. Safe to swim immediately after application, it’s ideal for seasonal water maintenance and long-term protection.

Available in 8kg and 20kg containers, this increaser is perfect for all pool and spa sizes, from small hot tubs to large inground pools.

✔ Key Benefits

Raises calcium hardness quickly and safely
Completely soluble, fast-acting formula
Prevents foaming, etching, and corrosion
Protects heaters, pumps, plumbing, and pool surfaces
Safe for vinyl, fiberglass, acrylic, plaster, and concrete
Swim immediately after application

How Many Containers You Need per Season

Pool Type	Approx. Volume (Litres)	Total Calcium Needed (per season)	4kg Container(s) Needed	20kg Container(s) Needed
Hot Tub / Spa	1,500–4,000 L	75–100 g per adjustment, 4–6 adjustments	1	–
8–10 ft Round Above Ground	5,000–8,000 L	500–600 g	1	–
12 ft Round Above Ground	10,000–12,000 L	1–1.5 kg	1	–
15 ft Round Above Ground	15,000–18,000 L	2–2.5 kg	1	–
12x18 ft Oval Above Ground	13,000–16,000 L	1.5–2 kg	1	–
15x24 ft Oval Above Ground	20,000–25,000 L	2.5–3 kg	1	–
Small Inground Pool	30,000–40,000 L	4–5 kg	1	–
Medium Inground Pool	50,000–60,000 L	6–7 kg	2	–
Large Inground Pool	70,000–80,000 L	8–10 kg	3	1

Note: Table assumes seasonal maintenance with 4–6 treatments. Actual dosage may vary depending on starting calcium levels.

Directions for Use

Test Water: Determine current calcium hardness.
Calculate Dose: Use approximately 25 g per 1,000 litres per adjustment.
Apply: Broadcast evenly across pool or spa water while the pump is running.
Circulate & Retest: Allow full circulation and retest before the next adjustment.

Protect your investment: Regular calcium maintenance prevents corrosion, scaling, and foaming, keeping your spa or pool safe, clean, and enjoyable all season.