Shower head
Blocked by the same carbonate deposit as a kettle, and finished in the one coating that most descaling products are excluded from.
Precautions
- Check the manufacturer's instructions
- Test on an inconspicuous area first
- Never mix with other cleaning products
Start here
What this is, what tends to go wrong with it, and what to do about it.
Made from
What tends to go wrong
A hard, chalky calcium carbonate deposit left by hard water. Dissolved by acids, essentially untouched by detergents.
Why it is difficult: Water hardness, Crystallisation, Adhesion and cohesion
- Dustvia its material
Mostly textile fibres and skin, held by static as much as by gravity — which is why a dry cloth on a plastic surface makes it worse.
Why it is difficult: Static and dust, Mechanical action and abrasion, Why different surfaces get different dirt, Surface roughness
- Mouldvia its material
A living growth, not a stain. Killing it and removing the staining are two separate jobs, and neither addresses the moisture that caused it.
Why it is difficult: Porous and non-porous surfaces, Moisture control and recurrence, Cleaning, sanitising and disinfecting, Organic load, Surface roughness
- Mildewvia its material
The flat, powdery surface growth that appears on damp fabric, grout and shower curtains — and the carpet trade's procedure for it names no bleach at all.
Why it is difficult: Moisture control and recurrence, Porous and non-porous surfaces, Organic load
- Mould fungivia its material
The organisms behind the marking. Around 1.5 million species, each with its own conditions — and killing them does not end the exposure they created.
Why it is difficult: Organic load, Moisture control and recurrence, Biofilm
- Soap scum· no established method
Not scale and not dirt: a metal soap formed when hard water meets true soap. It is the reason a shower screen films over in one house and not another.
Why it is difficult: Insoluble metal soaps, Water hardness, Evaporative deposition, Adhesion and cohesion, Why different surfaces get different dirt
A concentrated water-soluble dye with nothing else in it. Nothing has to be emulsified or dissolved — the only question is whether the surface has taken the colour up.
Why it is difficult: Capillary absorption, Dye migration and colour bleeding
A sticky, yellow-brown tar film deposited everywhere at once. It is the reason a room smells after everything visible has been cleaned.
Why it is difficult: Adsorption of odour molecules, Solubility and polarity
Coloured by turmeric in most prepared mustards, and curcumin is a pH indicator — which is why an alkaline cleaner turns a yellow mark red.
Why it is difficult: pH indicators in stains, Fat-soluble pigments, Photodegradation, Pigment retention
The commonest cleaning problem that is not dirt. The tackiness is the plastic's own additive arriving at the surface, which is why wiping it off works for a week.
Why it is difficult: Plasticizer migration, Damage versus soiling
Already everywhere, water-repellent, and resistant to drying out. Removing them is not the goal, because it is not achievable — denying them moisture is.
Why it is difficult: Moisture control and recurrence, Water-repellent and water-attracting surfaces
The science behind this: Polishing removes metal, Solvent crazing, Static and dust, Solvents and polymers, Plasticizer migration, Moisture control and recurrence
In detail
A shower head blocks because hard water evaporating in and around the nozzles leaves calcium carbonate behind, and the deposit builds inside the outlets where nothing can reach it mechanically. The chemistry is identical to a kettle's and the answer is the same in principle — an acid converts the insoluble carbonate to a soluble salt — but the surface is not the same, and that is where domestic advice usually goes wrong. Most shower heads are plated: chrome over brass or over plastic, and a fittings manufacturer excludes abrasive cleaners and solvents from its finishes and asks for water to be blotted dry rather than left to evaporate. Where a soak is being considered, three cautions apply: prolonged acid contact attacks some plated finishes, the fitting's own manufacturer may prohibit descaling agents outright, and a head with a hidden plastic insert may not survive what the visible metal would. Drying the head after use prevents the deposit forming.
Related
- Shower head is made from Chrome plating
- Shower head is made from Household plastics
- Shower head is made from Silicone sealant
- Shower head is commonly affected by Limescale
- Shower head is commonly affected by Soap scum
Hacks and claims involving this
Sources for this page
Sources
KALLISTA (Kohler Co.) · Manufacturer documentation
Relied on for: That abrasive cleaners and solvents are excluded from every finish, that acid is excluded from PVD finishes, and that water left to evaporate on metal forms deposits, so the finish is blotted dry. (states this directly)
Care & Cleaning: Toilets or Lavatories Made of Vitreous China
STERLING (Kohler Co.) · Manufacturer documentation
Relied on for: That splashes of cleaner are wiped from plastic or plated surfaces immediately. (states this directly)