A highly corrosive, strong mineral acid. Used to etch concrete and brick surfaces. Has major industrial uses and is a common laboratory reagent. Used for pickling of steel to remove rust or iron oxide scale from iron and steel. Lowers pH levels in water.

Spirits of Salt Common Uses

  • Brick & Paver Cleaning
  • Concrete Cleaning
  • Surface Rust Removal
  • Acid Washing
  • Reduces Alkalinity
  • Reduces pH Levels
  • Acid Brick Cleaner
  • Concrete Etching


  • Wear personal protective equipment when handling product. Always add acid to water, never water to acid. Use plastic containers (not metal) for mixing. Only prepare sufficient diluted material for the job. Apply evenly to cleaned surface with a watering can or broom. Allow 5 minutes for acid to react with surface, then wash off using water and a soft broom.

Brick & Paver Cleaning

  • 1 part Acid : 25 parts water.

Exposing Aggregate

  • 1 part Acid : 16 parts water.

Overlaying of Old concrete

  • 1 part Acid : 8 parts water.

Acid Washing

  • 1 part Acid : 10 parts water.

Concrete Cleaner:

  • 1 part Acid : 20 parts water.

pH Decreasing.

  • Adjusting pH levels in water for hot tubs, swimming and spa pools, which should be maintained at a pH Level between 7.2 to 7.8. Note: Spirits of Salt lowers pH Levels and Sodium Bicarbonate raises pH Levels.
  • We are often asked “What lowers pH” or “How do I lower pH” so the following chart has been included.

pH level reducing table using Spirits of Salt (Hydrochloric Acid – Muriatic Acid)

pH litres mls
7.9 – 8.0 10,000 125
8.0 – 8.1 10,000 141
8.1 – 8.2 10,000 156
  • Note this chart is a guide, If your high pH reading requires more than the maximum amount to be added at any one time, then you will have to add the chemical in increments, allowing 6 hours between applications. E.g. maximum dose for a 50,000 litre pool is 500ml of acid. For more information contact your local pool shop.


Sometimes referred to as Spirit of Salt

Note we are also bulk Hydrochloric Acid suppliers in New Zealand.
Industrial customers who buy Hydrochloric Acid are advised to download and read the Material Safety Data Sheet below.