Skip to product information
1 of 7

Borax

Borax

Regular price $13.90
Regular price Sale price $13.90
CLEARANCE Back in stock soon

When hard water and stubborn grime stop your cleaning products doing their job, Borax gives them the boost they need. It helps your soaps and cleaning recipes work more effectively, so you can get better results without adding more product or reaching for another specialised cleaner.

Quantity

Borax softens hard water and maintains useful alkalinity, helping soap and the other ingredients in your recipe spend more time cleaning and less time fighting the water.

What it is & how it works

Borax is sodium tetraborate decahydrate, a naturally occurring mineral salt found in borate deposits formed where mineral-rich water has evaporated over long periods.

Dissolved in water, it creates a mildly alkaline solution at around pH 9.2–9.5. That alkalinity helps loosen oily grime, while Borax also buffers pH and helps manage hard-water minerals that can interfere with soap and cleaning performance.

This puts it neatly between Bicarb and Washing Soda: more cleaning power than Bicarb, but considerably less alkaline than Washing Soda.

How you'll use it

✅ Multi-Purpose Cleaning Paste

Adds strength to your paste for jobs like grout, sinks, stovetops and other durable surfaces where mild cleaners are not enough

✅ In the Laundry

Forms the alkaline backbone of your DIY Laundry Powder, helping loosen dirt and grease while softening hard water so soap can work more effectively

✅ Hard-Water Cleaning Booster

Use it where calcium and magnesium in hard water are getting in the way of soap and detergent performance

✅ Suitable for

  • Most washable, durable fabrics
  • Ceramic and porcelain
  • Grout and tiles
  • Stainless steel
  • Many hard household surfaces

❎ Avoid using on

  • Wool, silk, leather and delicate fabrics
  • Aluminium
  • Waxed or polished surfaces
  • Delicate or specialty finishes
Key Benefits

✅ Fume and fragrance free cleaning

It delivers heavy-duty cleaning power without producing the harsh, irritating chemical fumes common in commercial cleaners.

✅ Spend less on specialised cleaners.

Use the same inexpensive powder across laundry, cleaning pastes and other household jobs instead of buying a multiple cleaners.

✅ One powder. Plenty of jobs.

You would be surprised by the number of used for borax, from making slime to managing ants.

✅ Make simple recipes work harder.

Softens hard water and maintains useful alkalinity, helping soap and the other ingredients in your recipe spend more time cleaning and less time fighting the water.

✅ Extends Clothing Life

By preventing mineral buildup (which makes fabrics stiff and grey), it keeps your clothes looking new and lasting longer.

✅ Refill without the plastic pile-up.

Refill your reusable jar from a home-compostable Earth Bag instead of buying another plastic cleaning container.

Important Info

🫙 Storage

Keep sealed and dry. Humidity can cause Borax to cake or clump, but this does not necessarily mean it has lost its cleaning ability.

⚠️ Safety

Borax and Boric Acid are not the same thing, but Borax should still be treated as a cleaning chemical. Do not ingest. Avoid breathing dust or getting it in your eyes, wash hands after handling and keep securely stored away from children and pets.

View full details

Learn more about Borax

See where Borax sits between Bicarb and Washing Soda, how it helps control hard-water minerals and pH, and why those small changes can make soap and other cleaning ingredients perform much better. The deeper guide also explains the important difference between Borax and Boric Acid and puts the safety discussion into context.

  • 5 stars: 6 (75%)
  • 4 stars: 1 (13%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 1 (13%)
M
Melanie M. (Australia)
Powerhouse

Borax is a powerhouse product great at removing stains. I use in my toilet, bathroom, kitchen and wash to help lift grime easily

M
Melanie M.
Powerhouse

Borax is a powerhouse product great at removing stains. I use in my toilet, bathroom, kitchen and wash to help lift grime easily

M
Mandy G.
Didn’t receive my order

Extremely disappointed, I was following tracking and it said parcel wasn’t collected from under your sink. I have countless times tried to contact Annalisa and she will not respond to me or refund my money.

K
Kylie M.
Great

Great

N
Nick L.
great product

great product

E
Elisabeth L.
Under Your Sink Products

I’ve bought several products from Under Your Sink since I’ve decided to do as much of our cleaning greener. I’m impressed by the packaging (brown paper bags), I’m close by so I can pick up, and I’d never go back to non-green cleaners, not even eco cleaners. I’ve used them for cleaning the bathroom, including shower screen and loo, in the laundry for normal washing and oxygen bleaching, and I’m about to make dishwasher tablets. We have a worm-farm black water system so using worm friendly products is important.

A
Ange O.
love the packaging

Great size for so many cleaning solutions
Love the eco friendly packaging

C
Carmen C.
Laundry powder

Love it, great for making DIY laundry powder!