Household cleaning
Finish Dishwasher Salt dupe
Why pay around £4.50 for Finish? The bulk active is PDV / water-softener salt (sodium chloride, coarse) — 73% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Finish Dishwasher Salt
2 kg · £4.50 typical snapshot
None (coarse vacuum-dried salt granules)
2 · Active
Sodium chloride
100% on the label
7647-14-5NaCl
Bulk PDV / water-softener salt (sodium chloride, coarse)
3 · Mix
Use neat in the dishwasher salt compartment — do not dissolve first
£0.60 per working litre · 73% less than the shelf pack
- Active
- Sodium chloride
- CAS
- 7647-14-5
- Dupe
- PDV / water-softener salt (sodium chloride, coarse)
- Saving
- 73% / 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
“Prevents limescale build-up in the dishwasher”
The chemical reality
Finish dishwasher salt is sodium chloride (CAS 7647-14-5) — coarse, high-purity salt for the machine’s ion-exchange softener. The molecule is the product. A 25 kg sack of PDV or water-softener salt is the same regenerant without the 2 kg grocery-box tax. This is not tablet detergent, not rinse aid, and not table salt (anti-caking agents can clog the softener).
Active vs filler
100% Sodium chloride · 0% carrier / filler — None (coarse vacuum-dried salt granules)
- Typical retail
- £4.50
- 2 kg
- Estimated active cost
- £1.20
- Scaled from bulk £14.99 / 25 kg
- Indicative markup
- 3.8×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 2 kg pack of Finish Dishwasher Salt typically retails around £4.50 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: Prevents limescale build-up in the dishwasher; Softens water so detergent works harder; and Recommended by leading dishwasher manufacturers.
The catch: Finish dishwasher salt is sodium chloride (CAS 7647-14-5) — coarse, high-purity salt for the machine’s ion-exchange softener. The molecule is the product. A 25 kg sack of PDV or water-softener salt is the same regenerant without the 2 kg grocery-box tax. This is not tablet detergent, not rinse aid, and not table salt (anti-caking agents can clog the softener).
- “Prevents limescale build-up in the dishwasher”
- “Softens water so detergent works harder”
- “Recommended by leading dishwasher manufacturers”
Proprietary Blend & Dosage Breakdown
The labelled active is Sodium chloride at 100%. Everything else in the pack is none (coarse vacuum-dried salt granules).
Even when the pack is sold as “pure” or ready-to-use, the dose that actually does the work is Sodium chloride. The rest is how they get it into a bottle you will pick up.
Branded working strength is whatever comes out of the bottle. The bulk alternative is 100% PDV / water-softener salt (sodium chloride, coarse), mixed to Use neat in the dishwasher salt compartment — do not dissolve first.
- Labelled active
- Sodium chloride
- 100%
- Carrier
- None (coarse vacuum-dried salt granules)
- Retail pack
- 2 kg · £4.50
The Active Chemical Alternative (Dupe Stack)
The dupe stack is PDV / water-softener salt (sodium chloride, coarse) at 100% bulk. Indexed as CAS 7647-14-5, formula NaCl. Buy it as 25 kg for around £14.99 from Amazon UK.
Working strength: Use neat in the dishwasher salt compartment — do not dissolve first. Indicative cost £0.60 per diluted litre — 73% 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.
- Food-grade coarse salt only. Do not use iodised table salt or fine cooking salt — anti-caking agents can clog the softener valve.
- Pour granules neat into the dishwasher salt compartment until full (typically 200–400 g). Wipe spills off the stainless tub so they do not rust-spot. Run a cycle if the manual says so after a refill.
- 25 kg is twelve-and-a-half 2 kg Finish boxes. Store dry; salt cakes if it picks up moisture.
- This regenerates the ion-exchange resin. It is not a detergent, not a rinse aid and not a kettle descaler. Soft-water areas may not need it — check the machine manual.
Dilution recipe
0.25 L working batch
Working strength Use neat in the dishwasher salt compartment — do not dissolve first. Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
250 grams
PDV / water-softener salt (sodium chloride, coarse)
Water
0.25 litres
Carrier / diluent
0% concentrate · 100% 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 brandedFinish | Raw active dupeDupeStack |
|---|---|---|
| Product | Dishwasher SaltAmazon UK search — listing, not a confirmed seller | PDV / water-softener salt (sodium chloride, coarse) |
| Pack / unit | 2 kg · £4.50 | 25 kg · £14.99 |
| Active | Sodium chloride at 100%Carrier: None (coarse vacuum-dried salt granules) | 100% bulkNaCl |
| CAS number | Not disclosed on pack | 7647-14-5 |
| Working strength | Ready-to-use pack | Dilute Use neat in the dishwasher salt compartment — do not dissolve first |
| Cost per litre | £4.50 / pack | £0.60 / L mixed from bulk |
| Headline saving | Baseline | 73% cheaper |
| COSHH / PPE | Follow the branded SDS | Gloves. Chemical-resistant gloves (nitrile or neoprene) |
Active ingredient and cheaper alternative — FAQ
Can I put table salt in the dishwasher?
You should not. Table salt is the same NaCl (CAS 7647-14-5) but finer, often iodised, and usually cut with anti-caking agents that can block the softener. Use coarse PDV or labelled water-softener / dishwasher salt.
Is this the same as Calgon or soda crystals?
No. Dishwasher salt regenerates the machine’s ion-exchange resin. Soda crystals (sodium carbonate) are a laundry alkali. Calgon-style wash softeners are typically polycarboxylates or zeolite in the drum — a different job, and they do not fill the salt compartment.
How do you mix the Dishwasher Salt dupe stack?
Food-grade coarse salt only. Do not use iodised table salt or fine cooking salt — anti-caking agents can clog the softener valve. Pour granules neat into the dishwasher salt compartment until full (typically 200–400 g). Wipe spills off the stainless tub so they do not rust-spot. Run a cycle if the manual says so after a refill. 25 kg is twelve-and-a-half 2 kg Finish boxes. Store dry; salt cakes if it picks up moisture. This regenerates the ion-exchange resin. It is not a detergent, not a rinse aid and not a kettle descaler. Soft-water areas may not need it — check the machine manual.
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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More teardowns
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- Retail pack
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- Raw active
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Domestos Original Thick Bleach
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- Retail pack
- £2.20750 millilitres
- Raw active
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- Retail pack
- £3.50750 millilitres
- Raw active
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£22.00Save 73% / L
Indicative DIY stack