Biocide vs degreaser
Green algae on a path is a biology problem — quats (BAC/DDAC) or sometimes hypochlorite. Black oil patches under a car or a greasy diesel stain on concrete are chemistry problems — you need an alkaline detergent builder such as sodium metasilicate, not a walk-away biocide spray.
What metasilicate does
Metasilicate lifts grease and organic soil by raising pH and breaking surface tension. You scrub or brush, then rinse thoroughly. It is related to other alkalis (soda ash, caustic soda) but is not a drop-in swap — dose from the SDS and the teardown maths.
Safety
Causes burns. Gloves and goggles. Always add powder to water. Keep off aluminium, galvanised metal and soft paint. Do not mix with acids or bleach.
FAQ
- Is KilrockPRO the same as Patio Magic?
- No. Patio Magic is a quat biocide for algae. KilrockPRO is disodium metasilicate — an alkaline degreaser for oil and traffic grime. Different stain, different salt.
More patio & exterior guides
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How much patio chemical do you need? Measure first
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BAC vs DDAC vs bleach on patios — which active for which stain?
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Water-repellent, biocide or acid — which patio job needs which chemistry
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Driveway & TFR oil and grease: which solvent for which stain
Related teardowns
Live stacks this guide points at — mix maths and DIY affiliate links on each page.
Patio & exterior
Patio, Driveway & Masonry Cleaner
KilrockPRO
- Retail pack
- £14.005 litres
- Raw active
- Sodium metasilicate pentahydrate10213-79-3
This is not Patio Magic (BAC) and it is not Mortar Clen (HCl). KilrockPRO is a dilute alkaline masonry degreaser — disodium metasilicate (CAS 6834-92-0) with soda ash and a chelator. Metasilicate pentahydrate crystals mixed at about 30 g/L match the bottle strength; then dilute 1:20 for light stains as the pack does.
Patio & exterior
Grimex Intensive Cleaner
LTP
- Retail pack
- £33.005 litres
- Raw active
- Tetrapotassium pyrophosphate (TKPP)7320-34-5
Not a patio biocide (BAC/DDAC) and not brick acid. LTP’s 2025 SDS lists tetrapotassium pyrophosphate (~1–3%) with glycol ether and a little ammonia — a phosphate-builder scrub for grease and old wax. TKPP crystals at about 20 g/L match the bottle’s builder strength; then dilute as the pack does.
Patio & exterior
OIL-EX Oil Stain Remover
Lithofin
- Retail pack
- £16.56250 millilitres
- Raw active
- Low-aromatic C9–C10 white spirit plus fuller’s earth poultice64742-49-0
Lithofin OIL-EX is a solvent poultice, not an alkaline degreaser. The GB SDS lists C9–C10 hydrocarbons (CAS 64742-49-0) at 60–65%, C9 aromatics (CAS 64742-95-6) at 15–20%, and d-limonene (CAS 5989-27-5) at 0.5–1% in an absorbent paste. It is not KilrockPRO metasilicate, not LTP Grimex TKPP, and not Solvex benzyl alcohol. Low-aromatic white spirit plus fuller’s earth is the same solvent-and-absorb job without the 250 ml tube tax.
Patio & exterior
Wet & Forget Exterior Surface Cleaner
Wet & Forget
- Retail pack
- £34.005 litres
- Raw active
- Benzalkonium chloride (BAC 50)68424-85-1
A dilute quaternary ammonium biocide sold as a lifestyle patio product. The active is commodity BAC 50; the brand is paying for the trigger bottle and the television advert.
Patio & exterior
4-in-1 Patio Power
Jeyes
- Retail pack
- £16.004 litres
- Raw active
- Didecyldimethylammonium chloride (DDAC 50)7173-51-5
This is not old Jeyes Fluid (tar acids are gone). Patio Power is 1.75% DDAC — a twin-chain quat, not the benzalkonium in Patio Magic. Dilute DDAC 50 to about 0.35% and you have the same working spray as the 4 L bottle mixed 1+4.
Household cleaning
Original Washing Up Liquid
Fairy
- Retail pack
- £1.25320 ml bottle
- Raw active
- SLES 70% paste (sodium laureth sulphate)68585-34-2
Fairy is mostly water and SLES — the workhorse anionic surfactant in almost every UK washing-up bottle. A 25 kg drum of SLES 70% paste dilutes to hundreds of litres of 2% working liquor. You are paying for the green bottle and the scent, not a proprietary molecule.
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.