• Hard water treatment
  • Hypo-allergenic
  • Safe for anything washable
  • 80+ Treatments


Fight Stains. Soften Clothes. Brighten Whites.

Our biodegradable booster and hard water treatment is made from an environmentally friendly phosphate that brings out the best in Charlie’s Soap detergents. Without leaving any residue on your clothes or in your washing machine, it controls minerals in your wash water with just 1/2 tablespoon per load. Your septic system and washing machine will also be safe because our booster is completely soluble.
Hard water does not pose a health risk, but it can cause “scale” – mineral build-up in pipes and plumbing fixtures – that reduces the effectiveness of laundry soap. Charlie’s Soap Booster is a non-toxic, biodegradable phosphate that can safely eliminate problems associated with hard water all while remaining environmentally friendly.

Biodegradable Booster and Hard Water Treatment Product Details

  • Simple Ingredient – Our booster is made from an environmentally safe phosphate designed to soften water and leave no hard water scale.
  • Rinses Clean – Rinses completely from fabric, leaving behind no residue on your clothes that can irritate sensitive skin.
  • Hard Water Treatment – Removes problem minerals from your water that keep detergents from working properly.
  • Non-Toxic – Aids in biodegradation in the environment.
  • Septic Safe – When used in moderation, our formula is safe in septic and municipal water systems. Non-precipitating and will not form scale.

Additional information

Suggested Use

Tossing a scoop into the washing machine is all it takes to soften water and get a better clean with each load.


Potassium diphosphate

Septic Safe

Certain phosphates can safely eliminate problems associated with hard water and be environmentally friendly. They are only a problem with overuse. While septic safe in general, if you use it daily you may need to periodically replenish your septic system with an enzyme and germ replenishment product.


For Laundry:

Use at least 1/2 tbsp. of Charlie’s Soap Booster as needed per wash. Use 1 full tbsp. for tough stains or excessively hard water. Wash according to care instructions. Test on garments that may bleed or fade.

To Pre-treat Stains:

Add 1 tsp. of Charlie’s Soap Booster to Charlie’s Soap Laundry Pre-Spray to tackle really bad stains.

For Household Cleaning:

Add 1 tbsp. of Charlie’s Soap Booster per 32 oz. spray bottle of either Charlie’s Soap Indoor / Outdoor or Charlie’s Kitchen & Bath cleaners to make them even more powerful.