Consumer advocacy teardown
Non-Chlorine Shock / Spa Oxidiser alternative & active ingredient dupe
Stop paying £18.99 for Clearwater. The bulk active is Potassium monopersulphate triple salt (MPS) — 71% less per working litre than a typical pack.
- Active
- Potassium peroxymonosulphate (MPS)
- CAS
- 70693-62-8
- Dupe
- Potassium monopersulphate triple salt (MPS)
- Saving
- 71% / 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.
The Marketing Claim & The Catch
A typical 1 kg tub pack of Clearwater Non-Chlorine Shock / Spa Oxidiser is about £18.99 in pool & spa. That is a snapshot, not a live Amazon price — listings, sizes and deals move. The marketing line is that you are buying a finished lifestyle product, not a weighed chemical.
On the pack: Shock without adding chlorine or closing the spa for hours; and Restores sparkle after a heavy bather load.
The catch: ‘Non-chlorine shock’ is Oxone-type MPS — the same triple salt used in bulk oxidisers. A 1 kg spa tub is a markup on a 5 kg bucket. It oxidises organics; it is not a sanitiser on its own.
- “Shock without adding chlorine or closing the spa for hours”
- “Restores sparkle after a heavy bather load”
Proprietary Blend & Dosage Breakdown
The labelled active is Potassium peroxymonosulphate (MPS) at 85%. Everything else in the pack is potassium sulphate and potassium hydrogen sulphate (triple salt).
Even when the pack is sold as “pure” or ready-to-use, the dose that actually does the work is Potassium peroxymonosulphate (MPS). 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 85% Potassium monopersulphate triple salt (MPS), mixed to 0.012 g/L (12 g/m³ as a typical spa shock).
- Labelled active
- Potassium peroxymonosulphate (MPS)
- 85%
- Carrier
- Potassium sulphate and potassium hydrogen sulphate (triple salt)
- Retail pack
- 1 kg tub · £18.99
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Potassium monopersulphate triple salt (MPS) at 85% bulk. Indexed as CAS 70693-62-8, formula KHSO5. Buy it as 5 kg for about £28.00 from Amazon UK.
Working strength: 0.012 g/L (12 g/m³ as a typical spa shock). Indicative cost £0.00 per diluted litre — 71% 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.
- Wear gloves and goggles. Broadcast 12 g per m³ (about 12 g per 1,000 litres) with the pump running. Do not mix in a bucket with chlorine.
- MPS is an oxidiser, not a residual sanitiser. Keep bromine or chlorine in range.
- 5 kg is five 1 kg spa tubs. Store dry. Test after shocking — some kits read MPS as chlorine.
Mixing desk
Dilution calculator
Switch between filling a sprayer and covering a measured surface. Figures are educational estimates from the listed ratio — always check the SDS.
Formula
Potassium monopersulphate triple salt (MPS)
- Concentrate
- 18 g
- grams of solid
- Water
- 1,500 L
- carrier volume
- Batch cost
- £0.10
- 1,500 L working solution
- Saved vs retail
- £0.24
- 71% · retail £0.34
Estimated coverage at the listed rate: 1.5 m².
Side-by-Side Price & Potency Comparison
Head-to-head comparison
| Measure | Retail brandedClearwater | Raw active dupeDupeStack |
|---|---|---|
| Product | Non-Chlorine Shock / Spa OxidiserAmazon UK search — listing, not a confirmed seller | Potassium monopersulphate triple salt (MPS) |
| Pack / unit | 1 kg tub · £18.99 | 5 kg · £28.00 |
| Active | Potassium peroxymonosulphate (MPS) at 85%Carrier: Potassium sulphate and potassium hydrogen sulphate (triple salt) | 85% bulkKHSO5 |
| CAS number | Not disclosed on pack | 70693-62-8 |
| Working strength | Ready-to-use pack | Dilute 0.012 g/L (12 g/m³ as a typical spa shock) |
| Cost per litre | £18.99 / pack | £0.00 / L mixed from bulk |
| Headline saving | Baseline | 71% 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
What is the active ingredient in Clearwater?
Clearwater Non-Chlorine Shock / Spa Oxidiser is labelled as Potassium peroxymonosulphate (MPS) at 85%. The carrier is Potassium sulphate and potassium hydrogen sulphate (triple salt). Pack size: 1 kg tub. The bulk equivalent we index is Potassium monopersulphate triple salt (MPS) (CAS 70693-62-8).
Is Potassium monopersulphate triple salt (MPS) safe on the intended surface?
Used at the listed working strength (0.012 g/L (12 g/m³ as a typical spa shock)), the dupe is the same chemistry as the branded pack for pool and spa water once dosed from a test kit. That is not a blanket all-clear: read the supplier SDS, wear the listed PPE, keep acids away from hypochlorite, and follow UK HSE/COSHH rules. Wellness teardowns are supplements, not medicines.
Is there a cheaper alternative to Clearwater Non-Chlorine Shock / Spa Oxidiser?
Yes. The bulk equivalent is Potassium monopersulphate triple salt (MPS) (CAS 70693-62-8). Indicative saving 71% per working litre versus a typical £18.99 pack. Working strength: 0.012 g/L (12 g/m³ as a typical spa shock). Live shop prices move.
How do you mix the Non-Chlorine Shock / Spa Oxidiser dupe stack?
Wear gloves and goggles. Broadcast 12 g per m³ (about 12 g per 1,000 litres) with the pump running. Do not mix in a bucket with chlorine. MPS is an oxidiser, not a residual sanitiser. Keep bromine or chlorine in range. 5 kg is five 1 kg spa tubs. Store dry. Test after shocking — some kits read MPS as chlorine.
DupeStack provides chemical concentration data and educational mixing guides. Always review official manufacturer Safety Data Sheets (SDS) and comply with UK Health and Safety Executive (HSE) and COSHH regulations when handling concentrated substances. Some links on this site are affiliate links.
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DIY stack · 71% / L vs branded
£40.00indicative kit · Amazon cannot add a mixed search kit as one basket