Pool & spa
Clearwater Chlorine Stabiliser & UV Shield dupe
Why pay around £16.50 for Clearwater? The bulk active is Technical cyanuric acid granules — 78% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Clearwater Chlorine Stabiliser & UV Shield
1 kg tub · £16.50 typical snapshot
None (granules)
2 · Active
Cyanuric acid
100% on the label
108-80-5C3H3N3O3
Bulk Technical cyanuric acid granules
3 · Mix
0.015 g/L (15 g/m³ for +15 ppm CYA)
£0.00 per working litre · 78% less than the shelf pack
- Active
- Cyanuric acid
- CAS
- 108-80-5
- Dupe
- Technical cyanuric acid granules
- Saving
- 78% / 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
“Helps stop sunlight destroying outdoor pool chlorine”
The chemical reality
100% cyanuric acid in a 1 kg spa tub. The same granules sell in 5 kg lots at a fraction of the per-kilo price. Dose to a test kit (typically 30–50 ppm CYA), not a marketing scoop.
Active vs filler
100% Cyanuric acid · 0% carrier / filler — None (granules)
- Typical retail
- £16.50
- 1 kg tub
- Estimated active cost
- £3.60
- Scaled from bulk £18.00 / 5 kg
- Indicative markup
- 4.6×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 1 kg tub pack of Clearwater Chlorine Stabiliser & UV Shield typically retails around £16.50 in pool & spa. 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: Helps stop sunlight destroying outdoor pool chlorine; and Can reduce chlorine consumption.
The catch: 100% cyanuric acid in a 1 kg spa tub. The same granules sell in 5 kg lots at a fraction of the per-kilo price. Dose to a test kit (typically 30–50 ppm CYA), not a marketing scoop.
- “Helps stop sunlight destroying outdoor pool chlorine”
- “Can reduce chlorine consumption”
Proprietary Blend & Dosage Breakdown
The labelled active is Cyanuric acid at 100%. Everything else in the pack is none (granules).
Even when the pack is sold as “pure” or ready-to-use, the dose that actually does the work is Cyanuric acid. 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% Technical cyanuric acid granules, mixed to 0.015 g/L (15 g/m³ for +15 ppm CYA).
- Labelled active
- Cyanuric acid
- 100%
- Carrier
- None (granules)
- Retail pack
- 1 kg tub · £16.50
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Technical cyanuric acid granules at 100% bulk. Indexed as CAS 108-80-5, formula C3H3N3O3. Buy it as 5 kg for around £18.00 from Amazon UK.
Working strength: 0.015 g/L (15 g/m³ for +15 ppm CYA). Indicative cost £0.00 per diluted litre — 78% 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. 150 g in 10,000 litres raises CYA by about 15 ppm. Ideal outdoor range is usually 30–50 ppm — test first.
- Place granules in a skimmer sock or mesh bag in the skimmer. Run the filter until dissolved (often 24–48 hours). Do not dump on the liner.
- 5 kg is five 1 kg spa tubs. Store dry, away from chlorine shock in the same bucket.
Dilution recipe
10,000 L pool / spa volume
Working strength 0.015 g/L (15 g/m³ for +15 ppm CYA). Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
150 grams
Technical cyanuric acid granules
Water
10,000 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 brandedClearwater | Raw active dupeDupeStack |
|---|---|---|
| Product | Chlorine Stabiliser & UV ShieldAmazon UK search — listing, not a confirmed seller | Technical cyanuric acid granules |
| Pack / unit | 1 kg tub · £16.50 | 5 kg · £18.00 |
| Active | Cyanuric acid at 100%Carrier: None (granules) | 100% bulkC3H3N3O3 |
| CAS number | Not disclosed on pack | 108-80-5 |
| Working strength | Ready-to-use pack | Dilute 0.015 g/L (15 g/m³ for +15 ppm CYA) |
| Cost per litre | £16.50 / pack | £0.00 / L mixed from bulk |
| Headline saving | Baseline | 78% 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 Chlorine Stabiliser & UV Shield is labelled as Cyanuric acid at 100%. The carrier is None (granules). Pack size: 1 kg tub. The bulk equivalent we index is Technical cyanuric acid granules (CAS 108-80-5).
Is Technical cyanuric acid granules safe on the intended surface?
Used at the listed working strength (0.015 g/L (15 g/m³ for +15 ppm CYA)), 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 Chlorine Stabiliser & UV Shield?
Yes. The bulk equivalent is Technical cyanuric acid granules (CAS 108-80-5). Indicative saving 78% per working litre versus a pack that typically retails around £16.50. Working strength: 0.015 g/L (15 g/m³ for +15 ppm CYA). Live shop prices move.
How do you mix the Chlorine Stabiliser & UV Shield dupe stack?
Wear gloves and goggles. 150 g in 10,000 litres raises CYA by about 15 ppm. Ideal outdoor range is usually 30–50 ppm — test first. Place granules in a skimmer sock or mesh bag in the skimmer. Run the filter until dissolved (often 24–48 hours). Do not dump on the liner. 5 kg is five 1 kg spa tubs. Store dry, away from chlorine shock in the same bucket.
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.
Related guides
Pool guide
Pool and spa basics: pH, chlorine and cyanuric acid without the brand kit
What Clearwater-style pH Plus, pH Minus, chlorine and CYA actually are — soda ash, dry acid, TCCA and stabiliser — with links to DupeStack teardowns.
Pool guide
Pool shock, bromine, floc and algaecide — not the same tub
Cal-hypo shock, dichlor granules, MPS oxidiser, BCDMH bromine, alum floc, copper algicide and thiosulphate reducer are different salts. Match the job before you buy a spa-shop tub.
Pool guide
Phosphate remover and polyquat — not a shock, and not copper
Lanthanum chloride drops phosphate. A polymeric quat is a copper-free algicide. Neither replaces trichlor, dichlor or cal-hypo, and neither is alum floc.
More teardowns
Pool & spa
Clearwater pH Plus Spa / Pool Balancer
Clearwater
- Retail pack
- £11.501 kg bottle
- Raw active
- Dense soda ash (sodium carbonate 99%)497-19-8
pH Plus is dense soda ash — 99% sodium carbonate, CAS 497-19-8. Pool-shop packaging turns a £2.70/kg commodity into an £11.50/kg ritual.
Pool & spa
Clearwater pH Minus
Clearwater
- Retail pack
- £9.991.5 kg
- Raw active
- Sodium bisulphate (dry acid)7681-38-1
pH Minus is dry acid — sodium bisulphate. Pool retail is a small tub; chemical suppliers sell it in 5 kg lots for a third of the per-kilo price.
Pool & spa
Clearwater Multifunction Chlorine Tablets
Clearwater
- Retail pack
- £42.005 kg
- Raw active
- TCCA 90% chlorine tablets (200 g)87-90-1
The tablet is 90% TCCA — the same stabilised chlorine used in bulk 200 g pucks. ‘Multifunction’ is a pinch of clarifier and a lot of packaging. Buy TCCA, dose from an SDS, and keep cyanuric acid in range.
£32.50Save 78% / L
Indicative DIY stack