Enduramaxx 300L Potable Tank review
Enduramaxx 300L Potable Drinking Water Tank
By Tom Calder
Key specs
The maker's figures.
- Capacity
- —
- Type
- Potable-rated fixed tank
If you want a fixed water reserve done properly, this is the grown-up option: a UK-manufactured 300-litre tank made from WRAS-approved polymer and supplied with a Bye-law 30 kit for drinking-water storage (Enduramaxx, 21 Oct 2026), with a 10-year warranty and a 600mm round footprint that tucks into a garage corner. That WRAS approval is the difference between 'food-grade plastic' and a material approved for drinking-water systems. Full it's around 300kg, so it wants level, load-bearing concrete — a garage or slab, never decking — and stored water still deserves periodic rotation.
- Best for
- The buy-once reserve — the only tank here made for drinking water (WRAS-approved polymer, Bye-law 30 kit), UK-made, 10-year warranty.
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Made from WRAS-approved polymer and supplied with a Bye-law 30 kit for drinking-water storage (Enduramaxx, 21 Oct 2026) — rare at this price
- UK-made, 10-year warranty, one-piece moulding
- 600mm footprint fits a garage corner
Worth knowing
- ~300kg full: solid ground-floor concrete only
- 'Slimline' means narrow, not small — it's 1.25m tall
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Our review
A 300-litre drinking-water tank moulded in Lincolnshire from a polymer with WRAS approval, 600mm across and 1.25 metres tall, shipped with the Byelaw 30 fittings stored drinking water needs. The point is the approval: this is a household tank made for water people will drink, not a food-grade drum pressed into service. It suits a home with a solid garage floor and the patience to rotate the water.
What it is
The government's Prepare campaign quotes the World Health Organisation's survival minimum of 2.5 to 3 litres a person a day; it says 10 litres is more comfortable once cooking and hygiene are included, so 300 litres is a week for a family of four at that rate.
What the Byelaw 30 kit does
Enduramaxx supplies the tank with a Bye-law 30 kit (Bye-law 60 in Scotland, it says). Its separately listed 1.5-inch kit comprises a screened breather, a screened warning-pipe unit, a ¾-inch dip-tube bend and a grommet for the vent pipe. That is what the Water Supply (Water Fittings) Regulations 1999 ask of a storage cistern: an overflow with a warning that keeps insects out, and a cover that excludes light and insects. Enduramaxx adds that in many installations a potable tank connected to the mains needs fluid category 5 approval, so a permanent plumbed feed is a job for a plumber who knows the regulations. Filling by hose from a tap and disconnecting it afterwards keeps things simple.
Where it can go
Enduramaxx's installation guide wants a surface that is smooth, level, firm and supports the whole base, with reinforced concrete the best answer in almost all circumstances: at least 600mm larger than the tank's dimensions and at least 102mm deep for tanks up to 2,500 litres, so a pad of roughly 1.2 metres across. A garage floor or a slab qualifies; a timber deck, a shed floor or a loft does not. The guide says to lift tanks only when empty, to let pipework at the outlet flex because the tank expands as it fills, that an impact, especially in the cold, may make it fail, and to fill it and check for leaks before relying on it. The polymer is UV-stabilised, and insulated versions are available.
How it compares
The 210-litre baffled tank on our water storage page is food grade but carries no WRAS approval, so it is a hose-fill reserve rather than a drinking-water cistern, its tap kit is an add-on, and full it weighs about 225kg. A new 1,000-litre food-grade IBC gives a tonne of water behind a 2-inch valve, more than most homes need. Six stackable 25-litre jerry cans give 150 litres you can carry. Our Enduramaxx 1000L Slimline is the same maker's rainwater tank: garden water, not drinking water.
Living with it
The 355mm lid is big enough to inspect and clean through, and Enduramaxx says the interior is smooth for that reason; a bolt-down lid and a side access hatch are options. The outlet needs a valve or tap of your own. Tap water is not treated for long storage, so our emergency water guide suggests refreshing it every six months or so, and black keeps light out. The standard warranty is two years, pro rata; registering within 21 days extends it to ten, and Enduramaxx voids it if the tank is not mounted and supported as instructed, and excludes damage from rigid outlet connections. Offloading on delivery is your job. Colours other than black count as bespoke and cannot be returned, nor can non-standard outlets.
Our verdict
Buy it if you want one fixed reserve of drinking water done to the standard the water regulations expect, you have a level concrete floor at ground level, and you will date the lid and rotate the contents. Skip it if you rent, live in a flat, or might need to move it: 300kg of water goes nowhere once it is in, and jerry cans or extra multipacks of bottled water cover the few days without mains water most households will ever face.
A researched review, built from the maker's specs, manual and UK listings; facts checked 21 Oct 2026. Sources: Enduramaxx — 300 Litre Potable Drinking Water Tank, SKU 172503-Potable (WRAS-approved MDPE, 600 × 1,250mm, 355mm lid, 1.5-inch outlet, Bye-law 30 kit, colours, fluid category 5 note, Lincolnshire manufacture); Enduramaxx — Vertical Tank Installation Guide 2019 (base 600mm larger than the tank, 102mm deep up to 2,500 litres, reinforced concrete, lift only when empty, flexible connections, impact at low temperature, fill test); Enduramaxx — 1.5-inch Byelaw 30 Kit Complete, England and Wales (screened breather, screened warning pipe, ¾-inch dip tube bend, grommet); Enduramaxx — Warranty (2-year standard pro rata; 10-year extension on registration within 21 days; rigid outlet and mounting exclusions); Enduramaxx — Delivery and Returns (offloading is the customer's responsibility; colours other than black and non-standard outlets non-refundable); Enduramaxx — Plastic drinking water tanks, UK manufacturer (tested for non-tainting; natural colour for inside installations only; smooth interior); WRAS — Material approvals (independent UK certification body; material approval shows compliance with BS 6920); legislation.gov.uk — Water Supply (Water Fittings) Regulations 1999, Schedule 2, paragraph 16 (storage cisterns: overflow with warning that excludes insects; cover excluding light and insects); legislation.gov.uk — Water Supply (Water Fittings) Regulations 1999, Schedule 1: fluid categories 1 to 5; GOV.UK Prepare — Get prepared for emergencies (quotes the WHO survival minimum of 2.5–3 litres a person a day; says 10 litres a day is more comfortable).
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for The step past jerry cans — a week-plus of household water in one food-grade tank.
in stock when checkedBest for The ceiling of home water storage — and only ever buy one NEW.
in stock when checkedBest for The clever middle ground — 40 litres one person can actually move.
Questions
How long will 300 litres of stored water last a family?
At the 10 litres a person a day the Prepare campaign gives for drinking, cooking and hygiene, four people get about a week. At its 2.5 to 3 litre survival figure, one person has over three months of drinking water.
Is the Enduramaxx 300L tank safe for drinking water?
It is made from a polymer with WRAS approval, which Enduramaxx says was tested for not tainting water, and ships with a Byelaw 30 kit. The water still needs rotating every six months or so, and the tank kept clean and dark.
Can I put the Enduramaxx 300L tank in a loft or on decking?
No. Enduramaxx's installation guide calls for a smooth, level, firm base supporting the whole tank, preferably reinforced concrete at least 102mm deep and 600mm larger than the tank's dimensions. With 300kg of water in it, that means a ground-floor slab.
Does the Enduramaxx 300L tank come with a tap?
No. It has a 1.5-inch plastic male outlet as standard, with other outlets to order; a tap or valve is yours to add. The Byelaw 30 kit is included.
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