What Are Prill Beads Made Of? The Science Behind Magnesium Prill Beads

Magnesium prill beads have become a popular addition to home water routines across Australia — but what are they actually made of, and how do they work? Here’s a straightforward explanation.

Browse our magnesium prill beads or read our related guides: Can Prill Beads Be Used in Tap Water? and Do Prill Beads Remove Fluoride?

What Are Prill Beads Made Of?

Prill beads are made from magnesium oxide — derived from naturally occurring magnesium salts found in deep brine deposits. The process works like this:

1. Magnesium is extracted from brine deposits (typically 700–800 metres underground) using dolomitic limestone.
2. The resulting magnesium oxide is fired at very high temperatures, creating small, hard, ceramic-like pellets.
3. These pellets are insoluble in water — they don’t dissolve, which is why they last for years.

The end result is a small bag of dense, white beads that slowly release magnesium ions into water, raising its pH and improving its mineral content.

What Do Prill Beads Do to Water?

When placed in water, magnesium prill beads:

• Raise the pH — typically to around 7.4–8.0, making the water mildly alkaline
• Add magnesium — a beneficial mineral involved in hundreds of bodily processes
• Improve taste — water treated with prill beads has a noticeably softer, smoother flavour
• Reduce surface tension — which proponents suggest improves cellular hydration

What they don’t do: prill beads are not a water filter. They don’t remove chlorine, fluoride, bacteria, or heavy metals. For comprehensive filtration, use them alongside a benchtop water filter or reverse osmosis system.

How Long Do Prill Beads Last?

Because magnesium oxide doesn’t dissolve in water, prill beads are extremely long-lasting. Most users find they remain effective for 12–24 months of regular use before their ability to raise pH gradually diminishes. They’re a one-time purchase that provides ongoing benefit — far more economical than buying bottled alkaline water.

How to Use Prill Beads

1. Rinse the bag under running water before first use.
2. Place in a glass or ceramic container (up to 5 litres).
3. Fill with drinking water and leave for 24 hours before first use.
4. Drink one-third to one-half of the water and refill — the beads will treat the new water within a few hours.
5. Store away from direct sunlight to prevent algae growth in the container.

They can also be used in the bath, for soaking fruit and vegetables, in cooking water, and in humidifiers.

Frequently Asked Questions