What does it do?
It reduces calcium hardness in pool water to prevent scale formation and corrosion, protecting surfaces and equipment. It is also called Cal Stop and helps eliminate calcium build-up on pool surfaces, salt water chlorinators and chlorinator cells, improving the efficiency and lifespan of your salt system.

How does it work?
The active ingredient (Hydroxyethylidene Diphosphonic Acid at 200g/L) chelates calcium ions, lowering hardness levels effectively. It also helps break down existing calcium deposits and organic grime on chlorinator cells, without affecting precious metals like titanium, unlike harsh alternatives that contain Hydrochloric Acid.

How is it applied?
Test your water to check the calcium hardness (ideal range: 200–400 ppm), then slowly pour the required dosage around the pool perimeter with the pump running, allowing 24 hours for full circulation. For stubborn scale in chlorinator cells, dosage and contact time may assist in lifting deposits.

Is it safe for all pools?
Yes, it’s compatible with all pool sanitizers and safe for use in various pool types and spas, including those with Quartzon, fibreglass, vinyl, pebblecrete and exposed aggregate finishes.

Dosing Multiple Chemicals or Need to Swim Soon?

We have a detailed Pool Chemical Wait Times and Chemical Interactions Guide that you can check here.

Water TechniX Calcium Down – Pool Hardness Decreaser and Calcium Stop

Water TechniX Calcium Down & Cal Stop is a high-quality chemical solution designed to effectively reduce calcium hardness levels in swimming pool and spa water. Maintaining the right calcium hardness is essential for preventing scaling and corrosion, ensuring the longevity of your pool's surfaces and equipment.

Key Benefits:
Essential for Water Balance: Helps to maintain the correct calcium levels in your pool water, keeping it safe for use.
Protects Pool Surfaces and Equipment: Prevents scaling and corrosion that can damage your pool’s finish and equipment.
Reduces Scale Formation: Lowers calcium hardness to the ideal range of 200-400 ppm, reducing the likelihood of calcium buildup.
Chelates Trace Metals: Assists in controlling unwanted staining of pool surfaces by keeping metals like iron and copper in solution.
Improves Chlorinator Efficiency: Dissolves calcium and organic build-up from salt chlorinator cells, increasing performance and prolonging cell life.
Safe on Precious Metals: Gentle formulation protects expensive cell materials without the damage caused by hydrochloric acid.
Reusable and Cost-Effective: Use as needed without waste, offering better value over single-use acidic solutions.
Compatible with All Pool Surfaces and Sanitisers: Works in all pool types and is safe for Quartzon, exposed aggregate and more.
Made in Australia: High-quality product designed and manufactured locally, supporting Australian businesses.

How to Apply:

Dosage: Use 500mL per 10,000L to reduce calcium hardness by approximately 25 ppm. For ongoing maintenance, use 60mL per 10,000L.

Directions: Before use, increase pH to 7.8–8.2 and backwash or clean the filter. Add the product evenly around the pool edges and run the filter continuously for 72 hours. Backwash or clean the filter again 24 hours after application. After treatment, reduce pH to the normal range of 7.2–7.8 and clean the filter once more. Avoid swimming during treatment and do not add other chemicals during this time.

Water TechniX Calcium Down Details:

• Active Ingredient: 200g/L Hydroxyethylidene Diphosphonic Acid
• Packaging: 1L resealable bottle
• Dosage: 1L treats 30,000 litres of pool water
• Made in Australia

Why Choose Water TechniX:

• Cost-Effective: Save up to 50% compared to traditional pool chemicals.
• Top Quality: Designed to eliminate up to 4X more bacteria and improve water balance with low-residual ingredients.
• Support Local: Proudly made and tested in Australia, supporting Aussie businesses.
• Proven Performance: Rigorous testing ensures effectiveness across all pool types.
• Time-Saving: Maintain your pool with ease using single-dose bottles that simplify the process.

Always wear safety protection and follow label instructions when handling pool chemicals.

Download our printable 7-in-1 test strip dosage guide here to make the best use of your pool chemicals.

Aussie-made, fast-acting pool chemicals designed for DIY clarity—perfect for salt, mineral, or chlorine pools. Covers the essentials people need in their pools shock, algaecide, black spot, clarifier, flocculant, stain remover & scale control, phosphate remover, plus pH Up/Down, alkalinity, calcium hardness, and stabiliser (CYA) to balance water fast. Simple, step-by-step dosing for clear, swim-ready water without the guesswork.