Limescale in Perth.
What it costs. How to fix it.

Yes for most people. Ion exchange softening adds a small amount of sodium to your water — roughly 30mg/L of added sodium for every 100mg/L of hardness removed. For Perth water at 200mg/L hardness, that's about 60mg of sodium per litre — well within drinking water safety limits. However, people on strict low-sodium diets (severe hypertension, kidney conditions) should consult their doctor or choose TAC instead. TAC adds zero sodium. Both technologies still produce drinking-safe water.

This is the most common confusion about TAC technology. Hard water test strips measure dissolved calcium and magnesium ions. TAC doesn't remove these ions — it converts them into stable microscopic crystals that physically can't bond to pipes or surfaces. The hardness minerals are still in the water (which is actually good for taste and health), but they can no longer form scale. If you want test-strip-soft water, you need ion exchange resin instead. If you want scale prevention without salt or added sodium, TAC is the right choice.

TAC is a relatively newer technology (commercial deployment from the mid-2000s) compared to ion exchange resin (1950s+), and the salt-softener industry has historically pushed back against it for commercial reasons. However, TAC media has independent NSF/ANSI 372 certification and DVGW certification (a respected German standard) for scale reduction. Multiple independent studies confirm 88-95% scale reduction on appliances at typical residential hardness levels. The University of Arizona has been particularly active in studying salt-free alternatives. It's not "magnetic water conditioning" (which is unproven) — TAC is a genuine physical-chemistry process.

No. If your suburb is below 80mg/L hardness — Subiaco, Kalamunda Hills, parts of the inner east — adding a resin or TAC stage to your filtration is unnecessary spend. You'd still benefit from a carbon block filter for chlorine taste reduction, but the scale prevention stage is overkill. Check your suburb on our water quality map first. We have customers on softer water suburbs who run 2-stage carbon-only systems and that's the right choice for them.

Partially. TAC and ion exchange both prevent new scale from forming, and over time some existing scale can dissolve back into the now-softer (or TAC-conditioned) water that flows over it. But this is a slow process — months to years depending on the existing build-up. For heavily scaled hot water systems, a one-time descaling service combined with installing scale prevention afterwards is more effective. Heavy descaling isn't something we do, but a licensed plumber can quote the descaling service if it makes sense for your system.

Significant. Perth town water (via the Water Corporation supply) ranges 35-300+ mg/L depending on suburb and source — most of which is treatable with TAC. Perth bore water — used for some gardens and historically more homes — can be much harder, with hardness levels of 500+ mg/L not unusual. Bore water often also has iron staining, manganese, and elevated TDS issues that go beyond just hardness. For bore water households, ion exchange resin is usually the right answer, often combined with additional pre-treatment stages.

It depends on the technology and the cartridge format. For cartridge-based whole-home systems (15" or 20" × 4.5" housings) we recommend annual replacement of the scale prevention stage regardless of whether it's resin or TAC media. This isn't strictly because the media is fully exhausted — it's because the sediment and bacterial film accumulating on the cartridge surface degrades performance over time. For larger standalone TAC tanks (separate from cartridge systems) the media itself can last 5-8 years before replacement is needed.