When a shower head starts spraying sideways, the holes are not worn out; they are scaled shut. The deposit is calcium carbonate from the water supply, and it dissolves in acid rather than in pressure, detergent or bleach.
Acid dissolves the blockage, bleach does not
Blocked shower head jets are limescale, so the fix is acid, not more pressure. Soak the head in a diluted descaler or a vinegar bag overnight, flush, and scrub the face with a soft brush; for plastic heads use a weaker dilution and shorter dwell time.
Prices are Freshway catalogue prices as at 16 September 2026 and are subject to change. Confirm the current price, and whether GST applies, before quoting.
The bag method, and when to use it
For a fixed head you cannot unscrew, fill a plastic bag with diluted descaler, tie it over the head so the face is submerged, and leave it for a few hours or overnight. This is the only method that reaches the internal channels without dismantling the fitting.
The same method works with white vinegar, at the cost of a slower reaction and a stronger smell. What it does not tolerate is bleach: chlorine attacks chrome and the rubber seals inside a handset, and it does nothing to the scale.
Removable heads: the quicker version
- Unscrew the head, and check the inlet washer and filter screen for grit.
- Soak the head face-down in diluted descaler for 30–60 minutes.
- Scrub the face with a soft brush and clear individual jets with a pin if a few remain blocked.
- Flush thoroughly, then refit with a new washer if the old one is perished.
| Product | Use | Price |
|---|---|---|
| Freshway Descaler 145 | Acid descaler for shower heads, taps, screens and kettles | A$48.00 |
| Agar Shower Star | Shower and washroom cleaner for soap scum and light scale | A$56.23 |
| Agar Sequal | Toilet, urinal and bathroom cleaning | A$35.59 |
| Sequal spray bottle, 750 mL | Empty bottle for diluted product on the round | A$5.50 |
Plastic heads, chrome heads and finishes
Chrome and stainless tolerate acid well at label dilution, provided you rinse afterwards. Plastic handsets and heads with a coloured coating are less tolerant: a strong acid soak dulls the finish and can soften the rubber seals. On those, use a weaker dilution, a shorter soak, and repeat rather than over-strengthening.
Brushed brass and some powder-coated finishes are the exceptions where acid should not be used at all. On those, remove the head and treat only the internal channels, or accept the scale.
Stopping the scale coming back
Two things help, and neither is a new shower head. Wipe the face of the head and the tapware with a microfibre cloth after the last shower of the day, which removes the water before the minerals can crystallise. And where the site is on hard water, treat the scale as a routine rather than an event: a monthly soak costs a few minutes and a diluted product, while a yearly replacement costs a fitting.
The hose, the tapware and the screen
The shower head is only the most visible part of the scale problem. The same minerals coat the flexible hose, which hardens and eventually splits; the tap and mixer, where scale stiffens the cartridge until it drips; and the screen, where the combined soap and mineral film is the hardest thing in the bathroom to remove.
The treatment is the same chemistry at different dilutions: acid for the mineral layer, then an alkaline or neutral bathroom cleaner for the soap scum sitting on top, then a squeegee or microfibre pass so the water does not stay on the surface. What you should not do is use an abrasive pad on chrome or on a coated screen, because the scratches hold scale and make the next clean harder.
Questions we get asked most
- What is the best thing to clean a shower head with?
- A diluted acid descaler, because the blockage is mineral scale. Vinegar works more slowly; bleach does not work at all and damages chrome and rubber seals.
- Should I soak my shower head in vinegar or bleach?
- Vinegar, if you are using a household product, and a descaler if you want it done in one soak. Bleach is the wrong chemistry for scale and the wrong chemistry for the finish.
- How do I clean the gunk out of my shower head?
- Soak the face in acid to dissolve the scale, then scrub with a soft brush and clear any remaining blocked jets with a pin. The gunk is scale plus biofilm, so a light disinfectant rinse afterwards is sensible.
- How do you remove mineral buildup from a shower head?
- Dwell time and acid concentration, in that order. Repeat a weaker soak rather than using one very strong solution, particularly on plastic and coated finishes.
- Can I put the shower head in the dishwasher?
- Not for scale. A dishwasher cycle is hot water and alkaline detergent, which does not dissolve calcium carbonate, and the heat can distort plastic components.
References
- SafeWork NSW — chemicals and other substances.
- NSW Environment Protection Authority — chemical handling and disposal.
Hard water across a building?
Tell us how many showers and how hard the water is, and we will set up a descaling routine that keeps the heads working without replacing them. Browse cleaning chemicals or ask our team.