Pool & spa
Lonza Bromine Activator / Bromide Bank Salt dupe
Why pay around £19.99 for Lonza? The bulk active is Sodium bromide technical grade (NaBr) — 64% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Lonza Bromine Activator / Bromide Bank Salt
2 kg tub · £19.99 typical snapshot
None (pure sodium bromide granules)
2 · Active
Sodium bromide (NaBr — bromine bank salt)
99% on the label
7647-15-6NaBr
Bulk Sodium bromide technical grade (NaBr)
3 · Mix
30 g per m³ start-up bank dose; 10 g/m³ maintenance
£0.00 per working litre · 64% less than the shelf pack
- Active
- Sodium bromide (NaBr — bromine bank salt)
- CAS
- 7647-15-6
- Dupe
- Sodium bromide technical grade (NaBr)
- Saving
- 64% / 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
“Establishes the bromide reserve so chlorine or MPS activates free bromine”
The chemical reality
Bromine activator is pure sodium bromide (NaBr, CAS 7647-15-6). The pool and spa trade sells it in branded 2 kg tubs; lab and photo suppliers sell the same technical-grade sodium bromide in 5 kg bags. There is no magic activation chemistry in the tub — you pay for the label and the small pack.
Active vs filler
99% Sodium bromide (NaBr — bromine bank salt) · 1% carrier / filler — None (pure sodium bromide granules)
- Typical retail
- £19.99
- 2 kg tub
- Estimated active cost
- £9.20
- Scaled from bulk £22.99 / 5 kg
- Indicative markup
- 2.2×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 2 kg tub pack of Lonza Bromine Activator / Bromide Bank Salt typically retails around £19.99 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: Establishes the bromide reserve so chlorine or MPS activates free bromine; Use on start-up or after a drain to rebuild the bromine bank; and Granular and easy to dose.
The catch: Bromine activator is pure sodium bromide (NaBr, CAS 7647-15-6). The pool and spa trade sells it in branded 2 kg tubs; lab and photo suppliers sell the same technical-grade sodium bromide in 5 kg bags. There is no magic activation chemistry in the tub — you pay for the label and the small pack.
- “Establishes the bromide reserve so chlorine or MPS activates free bromine”
- “Use on start-up or after a drain to rebuild the bromine bank”
- “Granular and easy to dose”
Proprietary Blend & Dosage Breakdown
The labelled active is Sodium bromide (NaBr — bromine bank salt) at 99%. Everything else in the pack is none (pure sodium bromide granules).
Even when the pack is sold as “pure” or ready-to-use, the dose that actually does the work is Sodium bromide (NaBr — bromine bank salt). 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 99% Sodium bromide technical grade (NaBr), mixed to 30 g per m³ start-up bank dose; 10 g/m³ maintenance.
- Labelled active
- Sodium bromide (NaBr — bromine bank salt)
- 99%
- Carrier
- None (pure sodium bromide granules)
- Retail pack
- 2 kg tub · £19.99
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Sodium bromide technical grade (NaBr) at 99% bulk. Indexed as CAS 7647-15-6, formula NaBr. Buy it as 5 kg for around £22.99 from Amazon UK.
Working strength: 30 g per m³ start-up bank dose; 10 g/m³ maintenance. Indicative cost £0.00 per diluted litre — 64% 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.
- Mild irritant; gloves and goggles when handling bulk. Not flammable. Store away from strong oxidisers.
- Start-up bank: dissolve 30 g per m³ of pool/spa water in a plastic bucket of pool water, then distribute around the returns with the pump running.
- Maintenance top-up: after a heavy bather load or water change, re-dose at 10–15 g/m³. Test bromide reserve with a test strip before each season opener.
- Follow NaBr with a small MPS shock or chlorine shock to activate the bromide bank into free hypobromous acid — NaBr itself does not sanitise.
- 5 kg at 30 g per m³ covers about 167 m³ of start-up treatments — a 10 m³ spa started 16 times, versus three 2 kg branded tubs.
Dilution recipe
10,000 L pool / spa volume
Working strength 30 g per m³ start-up bank dose; 10 g/m³ maintenance. Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
300 grams
Sodium bromide technical grade (NaBr)
Water
10,000 litres
Carrier / diluent
0% concentrate · 100% water by working volume (solids are dissolved into the water share).
Required PPE
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Side-by-Side Price & Potency Comparison
Head-to-head comparison
| Measure | Retail brandedLonza | Raw active dupeDupeStack |
|---|---|---|
| Product | Bromine Activator / Bromide Bank SaltAmazon UK search — listing, not a confirmed seller | Sodium bromide technical grade (NaBr) |
| Pack / unit | 2 kg tub · £19.99 | 5 kg · £22.99 |
| Active | Sodium bromide (NaBr — bromine bank salt) at 99%Carrier: None (pure sodium bromide granules) | 99% bulkNaBr |
| CAS number | Not disclosed on pack | 7647-15-6 |
| Working strength | Ready-to-use pack | Dilute 30 g per m³ start-up bank dose; 10 g/m³ maintenance |
| Cost per litre | £19.99 / pack | £0.00 / L mixed from bulk |
| Headline saving | Baseline | 64% 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
Why do I need sodium bromide if I already have bromine tablets?
BCDMH bromine tablets deliver both bromine and chlorine residual, but they deplete the bromide bank on their own over time. Sodium bromide pre-loads the reservoir so any subsequent chlorine shock or MPS oxidiser converts more efficiently into hypobromous acid. On start-up, dosing 30 g/m³ of NaBr sets the bank before the first tablet goes in.
Can I use sodium bromide in a chlorine pool?
Converting a chlorine pool to bromine requires pre-loading with NaBr first, then switching sanitiser. Do not add NaBr alongside TCCA tablets without changing the whole programme — chlorine and bromine overlap on standard test strips and tracking residuals becomes unreliable.
How do you mix the Bromine Activator / Bromide Bank Salt dupe stack?
Mild irritant; gloves and goggles when handling bulk. Not flammable. Store away from strong oxidisers. Start-up bank: dissolve 30 g per m³ of pool/spa water in a plastic bucket of pool water, then distribute around the returns with the pump running. Maintenance top-up: after a heavy bather load or water change, re-dose at 10–15 g/m³. Test bromide reserve with a test strip before each season opener. Follow NaBr with a small MPS shock or chlorine shock to activate the bromide bank into free hypobromous acid — NaBr itself does not sanitise. 5 kg at 30 g per m³ covers about 167 m³ of start-up treatments — a 10 m³ spa started 16 times, versus three 2 kg branded tubs.
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
PHMB and bromine pool care: chlorine-free sanitising decoded
How polyhexanide (PHMB) and sodium bromide work as chlorine-free pool sanitisers — activation chemistry, compatibility rules, and links to DupeStack teardowns.
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.
More teardowns
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Clearwater pH Plus Spa / Pool Balancer
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- 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.
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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.
£36.00Save 64% / L
Indicative DIY stack