Fluoride is unusual among water test parameters: at low levels it's deliberately added to mains water for dental health, but at higher levels — which occur naturally in some Australian groundwater — it becomes a problem. If you're on a bore, fluoride is worth knowing about.
The Australian Drinking Water Guidelines explained set the fluoride guideline at 1.5 mg/L. Sustained levels above that do not meet Australian Drinking Water Guidelines and should be addressed.
Where Fluoride in Water Comes From
- Natural geology — fluoride-bearing minerals in granite country and some sedimentary aquifers dissolve into groundwater. This is the main source for bore owners; our bore water safety guide covers regional patterns.
- Mains water — most Australian town supplies are fluoridated to around 0.6 – 1.1 mg/L, well under the guideline.
- Tank water — rainwater contains essentially no fluoride (more in our tank water safety guide).
What the Levels Mean
| Fluoride Level | What It Means |
|---|---|
| Under 1.0 mg/L | Typical of fluoridated mains water; within guidelines |
| 1.0 – 1.5 mg/L | Within guidelines but worth monitoring, especially with young children |
| Over 1.5 mg/L | Does not meet Australian Drinking Water Guidelines and should be addressed — risk of dental fluorosis with sustained exposure |
Dental fluorosis — mottling or white flecks on developing teeth — is the main concern from sustained excess fluoride, and it affects children while their teeth are forming. Very high levels over many years can also affect bones.
Testing and Treating Fluoride
Fluoride is invisible and tasteless at the levels that matter, so laboratory analysis is the only way to know your number — our guide on how to test your water explains how sampling works.
If your fluoride is above the guideline:
- Reverse osmosis — reliably reduces fluoride at the drinking tap
- Activated alumina filters — designed specifically for fluoride reduction
- Blending or alternative supply — for households with consistently high bore fluoride, using tank water for drinking is sometimes the simplest answer
Note that ordinary carbon jug filters and standard sediment filters do not remove fluoride.
Frequently Asked Questions
Is fluoride in bore water dangerous?
At low levels, no — fluoride is added to most Australian mains supplies for dental health. But some bores draw from geology with naturally high fluoride, and sustained exposure above the guideline value of 1.5 mg/L can cause dental fluorosis, particularly in children.
Does tank water contain fluoride?
Almost none. Rainwater carries no meaningful fluoride, which is one reason dentists sometimes ask whether your household drinks tank water. Fluoride testing matters mainly for bore and well supplies.
Can I remove fluoride from my water?
Yes — reverse osmosis and activated alumina filters reduce fluoride effectively. Standard carbon jug filters do not. Test first to confirm your level, then choose treatment to suit.
Want to know your fluoride level?
Test your bore or household water for fluoride and the parameters that matter alongside it — with plain-English results measured against the Australian Drinking Water Guidelines.
