Pool & spa
Clearwater Stabilised Chlorine Granules dupe
Why pay around £12.99 for Clearwater? The bulk active is Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl) — 55% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Clearwater Stabilised Chlorine Granules
1 kg tub · £12.99 typical snapshot
None (stabilised chlorine granules)
2 · Active
Sodium dichloroisocyanurate dihydrate (dichlor)
55% on the label
51580-86-0C3Cl2N3NaO3·2H2O
Bulk Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl)
3 · Mix
10 g/m³ (~5 ppm shock; 2 g/m³ raises ~1 ppm)
£0.00 per working litre · 55% less than the shelf pack
- Active
- Sodium dichloroisocyanurate dihydrate (dichlor)
- CAS
- 51580-86-0
- Dupe
- Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl)
- Saving
- 55% / 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
“Fast-dissolving granules for a quick chlorine boost”
The chemical reality
Clearwater’s 1 kg spa granules are sodium dichloroisocyanurate dihydrate (troclosene sodium, CAS 51580-86-0) — dichlor, not TCCA tablets and not Fi-Clor Superfast cal-hypo. About 2 g per 1,000 L raises free chlorine by 1 ppm; 10 g/m³ is a typical ~5 ppm shock. A 5 kg trade sack is the same salt. Dichlor adds cyanuric acid, unlike cal-hypo.
Active vs filler
55% Sodium dichloroisocyanurate dihydrate (dichlor) · 45% carrier / filler — None (stabilised chlorine granules)
- Typical retail
- £12.99
- 1 kg tub
- Estimated active cost
- £5.60
- Scaled from bulk £28.00 / 5 kg
- Indicative markup
- 2.3×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 1 kg tub pack of Clearwater Stabilised Chlorine Granules typically retails around £12.99 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: Fast-dissolving granules for a quick chlorine boost; Stabilised chlorine — more effective and long-lasting; and Minimal impact on pH — shock or daily dose.
The catch: Clearwater’s 1 kg spa granules are sodium dichloroisocyanurate dihydrate (troclosene sodium, CAS 51580-86-0) — dichlor, not TCCA tablets and not Fi-Clor Superfast cal-hypo. About 2 g per 1,000 L raises free chlorine by 1 ppm; 10 g/m³ is a typical ~5 ppm shock. A 5 kg trade sack is the same salt. Dichlor adds cyanuric acid, unlike cal-hypo.
- “Fast-dissolving granules for a quick chlorine boost”
- “Stabilised chlorine — more effective and long-lasting”
- “Minimal impact on pH — shock or daily dose”
Proprietary Blend & Dosage Breakdown
The labelled active is Sodium dichloroisocyanurate dihydrate (dichlor) at 55%. Everything else in the pack is none (stabilised chlorine granules).
Even when the pack is sold as “pure” or ready-to-use, the dose that actually does the work is Sodium dichloroisocyanurate dihydrate (dichlor). 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 55% Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl), mixed to 10 g/m³ (~5 ppm shock; 2 g/m³ raises ~1 ppm).
- Labelled active
- Sodium dichloroisocyanurate dihydrate (dichlor)
- 55%
- Carrier
- None (stabilised chlorine granules)
- Retail pack
- 1 kg tub · £12.99
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl) at 55% bulk. Indexed as CAS 51580-86-0, formula C3Cl2N3NaO3·2H2O. Buy it as 5 kg for around £28.00 from Amazon UK.
Working strength: 10 g/m³ (~5 ppm shock; 2 g/m³ raises ~1 ppm). Indicative cost £0.00 per diluted litre — 55% 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.
- Oxidiser. Gloves and goggles. Never mix dry with cal-hypo, TCCA, acids or organics — toxic chlorine gas. Pre-dissolve in a clean plastic bucket of pool water, then pour with the pump running.
- Maintenance: about 2 g per 1,000 L raises free chlorine by 1 ppm (Clearwater band). Weekly shock: about 10 g per 1,000 L for ~5 ppm. Target 1–3 ppm in a pool, 3–5 ppm in a spa. Retest after four hours.
- Dichlor adds cyanuric acid. Outdoors that helps; indoors it accumulates. Test CYA and do not stack dichlor on top of TCCA if stabiliser is already high.
- 5 kg at spa-tub prices is five 1 kg Clearwater tubs. Store cool, dry, sealed, away from acids and other pool salts.
- This is not MPS non-chlorine shock, not bromine (BCDMH), and not alum floc. Dose from a test kit.
Dilution recipe
10,000 L pool / spa volume
Working strength 10 g/m³ (~5 ppm shock; 2 g/m³ raises ~1 ppm). Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
100 grams
Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl)
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 | Stabilised Chlorine GranulesAmazon UK search — listing, not a confirmed seller | Sodium dichloroisocyanurate dihydrate (NaDCC / dichlor, ~55% available Cl) |
| Pack / unit | 1 kg tub · £12.99 | 5 kg · £28.00 |
| Active | Sodium dichloroisocyanurate dihydrate (dichlor) at 55%Carrier: None (stabilised chlorine granules) | 55% bulkC3Cl2N3NaO3·2H2O |
| CAS number | Not disclosed on pack | 51580-86-0 |
| Working strength | Ready-to-use pack | Dilute 10 g/m³ (~5 ppm shock; 2 g/m³ raises ~1 ppm) |
| Cost per litre | £12.99 / pack | £0.00 / L mixed from bulk |
| Headline saving | Baseline | 55% cheaper |
| COSHH / PPE | Follow the branded SDS | Gloves. Chemical-resistant gloves (nitrile or neoprene)Eye protection. Indirect-vent splash goggles — not ordinary spectaclesVentilation. Use outdoors or with mechanical extraction |
Active ingredient and cheaper alternative — FAQ
Is this the same as Clearwater multifunction tablets?
Same stabilised-chlorine family, different molecule and job. Tablets are trichloroisocyanuric acid (TCCA, CAS 87-90-1) — slow-dissolve pucks that also add CYA. These granules are dichlor (NaDCC dihydrate, CAS 51580-86-0) — fast dissolve for a dose or shock. Do not treat them as 1:1 swaps.
Is this the same as Fi-Clor Superfast shock?
No. Superfast is calcium hypochlorite (CAS 7778-54-3) — unstabilised, raises hardness, no extra CYA. Dichlor is stabilised and near pH-neutral. Indoor pools often prefer cal-hypo so CYA does not climb. Never mix the dry powders in a bucket.
How do you mix the Stabilised Chlorine Granules dupe stack?
Oxidiser. Gloves and goggles. Never mix dry with cal-hypo, TCCA, acids or organics — toxic chlorine gas. Pre-dissolve in a clean plastic bucket of pool water, then pour with the pump running. Maintenance: about 2 g per 1,000 L raises free chlorine by 1 ppm (Clearwater band). Weekly shock: about 10 g per 1,000 L for ~5 ppm. Target 1–3 ppm in a pool, 3–5 ppm in a spa. Retest after four hours. Dichlor adds cyanuric acid. Outdoors that helps; indoors it accumulates. Test CYA and do not stack dichlor on top of TCCA if stabiliser is already high. 5 kg at spa-tub prices is five 1 kg Clearwater tubs. Store cool, dry, sealed, away from acids and other pool salts. This is not MPS non-chlorine shock, not bromine (BCDMH), and not alum floc. Dose from a test kit.
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.
£40.00Save 55% / L
Indicative DIY stack