Household cleaning
Viakal Limescale Remover Spray dupe
Why pay around £3.50 for Viakal? The bulk active is Glycolic acid solution (70%) — 59% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Viakal Limescale Remover Spray
500 millilitres · £3.50 typical snapshot
Water, non-ionic surfactant and fragrance
2 · Active
Glycolic acid (alpha-hydroxy acid descaler)
10% on the label
79-14-1C2H4O3
Bulk Glycolic acid solution (70%)
3 · Mix
1:6 (70 ml into 420 ml water → ~10%)
£2.86 per working litre · 59% less than the shelf pack
- Active
- Glycolic acid (alpha-hydroxy acid descaler)
- CAS
- 79-14-1
- Dupe
- Glycolic acid solution (70%)
- Saving
- 59% / L
Saving is per litre of working-strength mix versus a typical pack price, not versus the DIY kit total. Shop prices move — always check the listing.
Label teardown
What the pack promises versus what the label chemistry actually is.
The marketing claim
“Removes limescale from tiles, taps and shower screens”
The chemical reality
Viakal's GB SDS lists glycolic acid (CAS 79-14-1) at 5–15% as the primary descaling active, not hydrochloric acid and not citric acid. Glycolic is a short-chain alpha-hydroxy acid that dissolves calcium carbonate gently enough for chrome and ceramic. Bulk 70% glycolic diluted to a 10% working spray is the same chemistry without the brand fragrance charge.
Active vs filler
10% Glycolic acid (alpha-hydroxy acid descaler) · 90% carrier / filler — Water, non-ionic surfactant and fragrance
- Typical retail
- £3.50
- 500 millilitres
- Estimated active cost
- £1.43
- Scaled from bulk £9.99 / 500 ml
- Indicative markup
- 2.5×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 500 millilitres pack of Viakal Limescale Remover Spray typically retails around £3.50 in household cleaning. That is a UK shelf-price snapshot for the maths on this page — not a live shop quote or a manufacturer RRP. Listings, sizes and deals move. The marketing line is that you are buying a finished lifestyle product, not a weighed chemical.
On the pack: Removes limescale from tiles, taps and shower screens; No harsh bleach odour; and Leaves surfaces shining.
The catch: Viakal's GB SDS lists glycolic acid (CAS 79-14-1) at 5–15% as the primary descaling active, not hydrochloric acid and not citric acid. Glycolic is a short-chain alpha-hydroxy acid that dissolves calcium carbonate gently enough for chrome and ceramic. Bulk 70% glycolic diluted to a 10% working spray is the same chemistry without the brand fragrance charge.
- “Removes limescale from tiles, taps and shower screens”
- “No harsh bleach odour”
- “Leaves surfaces shining”
Proprietary Blend & Dosage Breakdown
The labelled active is Glycolic acid (alpha-hydroxy acid descaler) at 10%. Everything else in the pack is water, non-ionic surfactant and fragrance.
At 10% active, most of what you pay for is carrier and packaging. The brand is selling convenience, fragrance and a label — not a uniquely potent molecule.
Branded working strength is whatever comes out of the bottle. The bulk alternative is 70% Glycolic acid solution (70%), mixed to 1:6 (70 ml into 420 ml water → ~10%).
- Labelled active
- Glycolic acid (alpha-hydroxy acid descaler)
- 10%
- Carrier
- Water, non-ionic surfactant and fragrance
- Retail pack
- 500 millilitres · £3.50
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Glycolic acid solution (70%) at 70% bulk. Indexed as CAS 79-14-1, formula C2H4O3. Buy it as 500 ml for around £9.99 from Amazon UK.
Working strength: 1:6 (70 ml into 420 ml water → ~10%). Indicative cost £2.86 per diluted litre — 59% below a typical branded pack on a per-litre basis, before you reuse leftover bulk.
Follow the mixing method and the supplier SDS. Wear the listed PPE. Do not mix incompatible oxidisers, acids or ammonia.
- Acid solution. Nitrile gloves and goggles. Add acid to water, never water to acid. Do not use on limestone, marble or calcite stone — it etches.
- For a limescale spray: measure 70 ml of 70% glycolic into a 500 ml trigger bottle, add 430 ml water, label clearly. Shake gently.
- Spray on shower screen, tiles or taps. Leave 2–5 minutes, wipe and rinse. For heavy limescale on shower screens, soak a cloth and press flat for 10 minutes.
- 500 ml of 70% concentrate makes about 3.5 litres of 10% working spray — seven of the 500 ml Viakal bottles.
- Keep away from anionic or cationic surfactants in closed bottles — use a plain water carrier. Rinse children's and pets' areas before re-entry.
Dilution recipe
0.5 L working batch
Working strength 1:6 (70 ml into 420 ml water → ~10%). Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
71 millilitres
Glycolic acid solution (70%)
Water
0.43 litres
Carrier / diluent
14% concentrate · 86% water by working volume (solids are dissolved into the water share).
Required PPE
Loading calculator…
Side-by-Side Price & Potency Comparison
Head-to-head comparison
| Measure | Retail brandedViakal | Raw active dupeDupeStack |
|---|---|---|
| Product | Limescale Remover SprayAmazon UK search — listing, not a confirmed seller | Glycolic acid solution (70%) |
| Pack / unit | 500 millilitres · £3.50 | 500 ml · £9.99 |
| Active | Glycolic acid (alpha-hydroxy acid descaler) at 10%Carrier: Water, non-ionic surfactant and fragrance | 70% bulkC2H4O3 |
| CAS number | Not disclosed on pack | 79-14-1 |
| Working strength | Ready-to-use pack | Dilute 1:6 (70 ml into 420 ml water → ~10%) |
| Cost per litre | £7.00 / L typical pack | £2.86 / L mixed from bulk |
| Headline saving | Baseline | 59% cheaper |
| COSHH / PPE | Follow the branded SDS | Gloves. Chemical-resistant gloves (nitrile or neoprene)Eye protection. Indirect-vent splash goggles — not ordinary spectacles |
Active ingredient and cheaper alternative — FAQ
Is glycolic acid the same as citric acid?
No — they are different organic acids. Citric acid (CAS 5949-29-1) is triprotic and tastes sour; it is the standard kettle and machine descaler. Glycolic acid (CAS 79-14-1) is a shorter chain alpha-hydroxy acid with a lower molecular weight, which means it penetrates limescale and grout more aggressively at lower concentrations. Viakal uses glycolic because it works faster on thick shower-screen scale.
Can glycolic acid damage chrome or stone?
At 5–10% it is safe on chrome, glazed ceramic and glass for the contact times on the label. Do not leave it on limestone, marble or natural stone — even mild acids etch calcite. Test a hidden spot first on grout.
How do you mix the Limescale Remover Spray dupe stack?
Acid solution. Nitrile gloves and goggles. Add acid to water, never water to acid. Do not use on limestone, marble or calcite stone — it etches. For a limescale spray: measure 70 ml of 70% glycolic into a 500 ml trigger bottle, add 430 ml water, label clearly. Shake gently. Spray on shower screen, tiles or taps. Leave 2–5 minutes, wipe and rinse. For heavy limescale on shower screens, soak a cloth and press flat for 10 minutes. 500 ml of 70% concentrate makes about 3.5 litres of 10% working spray — seven of the 500 ml Viakal bottles. Keep away from anionic or cationic surfactants in closed bottles — use a plain water carrier. Rinse children's and pets' areas before re-entry.
DupeStack provides chemical concentration data and educational mixing guides only. Wellness pages compare food supplements, not medicines or prescribed treatments. Always review the supplier Safety Data Sheet (SDS) and comply with UK Health and Safety Executive (HSE) and COSHH regulations when handling concentrated substances. Mixing and storage are at your own risk. Some links are affiliate advertisements (Amazon Associates, eBay Partner Network, and Awin when those programmes are live). Commissions do not change listed concentrations or calculator output.
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£18.00Save 59% / L
Indicative DIY stack