The Hidden Additive in Your Tap Water: Chloramines

May 15, 2026

The Hidden Additive in Your Tap Water: Why Chloramines Are Taking Over Australia’s East Coast

Photo by Deeva Sood of Warragamba Dam

If you live along the East Coast of Australia—from the sprawling suburbs of Sydney to the growing communities in South East Queensland—the water coming out of your tap might not be what you think. While we often associate the "pool smell" with chlorine, water authorities are increasingly switching to a different chemical duo: Chloramines.

At Sentry Water Filters, we’ve seen a surge in questions about why this change is happening and, more importantly, how it affects your home’s water quality.

What are Chloramines?

Chloramines are formed when ammonia is added to water that has already been treated with chlorine. This chemical reaction creates a more stable disinfectant known as monochloramine (NH2Cl).

Water authorities in major hubs like Sydney and Brisbane use this method because it offers several advantages for large-scale infrastructure:

Long-Lasting Protection: Unlike chlorine, which evaporates quickly, chloramines stay active much longer as water travels through kilometers of pipes.
Heat Resistance: In Australia’s warmer climates, standard chlorine breaks down rapidly. Chloramines are far more resilient to the heat.
Reduced "Chemical" Taste: Paradoxically, while it is a more persistent chemical, many people find it has less of the harsh "bleach" odor associated with free chlorine.

Why Your Standard Filter Isn't Enough

Many homeowners believe that a standard carbon filter or a basic Reverse Osmosis (RO) system will keep their water pure. Unfortunately, when it comes to the East Coast's ammonia-treated water, that isn't the case.

1. The Sediment Filter Limitation

A sediment filter is a vital "first line of defense," but it is strictly mechanical. It acts like a screen door, catching rust, silt, and grit. However, because ammonia and chloramines are dissolved in the water (like salt in the ocean), they sail straight through a sediment filter without being touched.

2. The Standard Carbon Problem

Standard Activated Carbon (GAC) works through "adsorption." While it is great at catching chlorine, chloramines require a much longer contact time to break the bond between the chlorine and ammonia. In a standard kitchen filter, the water often moves too fast for the carbon to actually "break" the chloramine molecule. You might remove the taste, but the chemical remains.

3. The Reverse Osmosis Challenge

Standard Reverse Osmosis membranes are actually quite sensitive. Chloramines can pass through standard membranes more easily than other contaminants. Furthermore, the presence of chloramines can actually degrade the RO membrane over time. To be effective, an RO system must be paired with high-quality carbon stages to protect the membrane and catch what it misses.

4. The Solution: Catalytic Carbon

To truly remove chloramines, you need Catalytic Carbon. Unlike standard carbon, catalytic carbon is specifically processed to facilitate chemical reactions. It doesn't just "trap" the chloramine; it acts as a catalyst to chemically break the bond between the chlorine and ammonia, neutralizing them both effectively.

The Risks of Ammonia in Your Home

If your filter isn't stripping the ammonia out, you face several issues:

Nitrification Risks: Excess ammonia can trigger "nitrification" in your home's plumbing. This is where bacteria convert ammonia into nitrites, which can actually accelerate the decay of your water quality.
Corrosion: Chloramines can be more aggressive than chlorine toward rubber seals, gaskets, and even copper piping.

The Verdict

"Safe" water doesn't always mean "ideal" water. By upgrading to a system designed for chloramines and ammonia, you ensure that the additives used by city councils stay at the curb.

Not sure which filter you need? Message our team at Sentry Water Filters today via our Contact Us page

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