Bottle with Filter Water

Ten bottles here, all of them built around the same idea: a filter in the drinking path, so you fill from a stream or a tap you do not trust and drink straight away. These are new, unbranded bottles, described from the maker's specification. Nothing here has been tested by us, which matters more in this category than in any other, so the specifications are attributed and the limits are stated.

What these filters do, and what they do not

Every filter on this shelf is a hollow-fibre membrane, typically 0.01 micron, usually with an activated carbon stage. That combination stops bacteria and protozoa, the things that make you ill from a British stream, a farm-runoff beck or a questionable campsite tap. It does not stop viruses. That is not a fault, it is the difference between a filter and a purifier, and almost nobody selling these explains it. In Britain the bacteria-and-protozoa risk is the one that matters. Travelling somewhere with a genuine viral risk in the water, this is not the right tool and you want a purifier, chemical treatment or boiling.

The carbon stage handles chlorine, taste and odour, and reduces some organic compounds. Where a listing says heavy metals, read it as a reduction rather than removal.

Flow rate is what decides whether you keep using it

The complaint that ends the relationship with a filter bottle is not the filtration, it is the effort. Sucking hard through a loaded membrane gets old fast, and plenty of these bottles end up in a cupboard because of it. So the flow rate is printed where the maker gives it, and the format is named: squeeze bottles are fastest, gravity-fed bottles need no effort but take their time, the press design does the work in one push, and one bottle here uses a battery pump. Pick the format for how you will actually use it.

The cartridge is the real cost

Every filter here is a consumable. Quoted lifespans on this shelf run from three months to 8000 litres, which is an enormous spread, so read that figure before you compare prices. A filter bottle with a cheap sticker and a short cartridge life is not the cheap option. Flow dropping off is the normal sign of a loaded filter: rinse or backflush it before assuming it is finished.

Two things that kill a membrane

Freezing is the first: water left inside and frozen splits the fibres, and a split membrane no longer filters anything while still appearing to work. The second is putting anything through it but water. Neither failure is visible, which is why both are worth the sentence.

Delivery and returns

UK delivery is free. Orders are processed within 3 to 5 business days and arrive within 10 to 20 business days. Returns or exchange within 30 days of delivery, unused and in original condition, approved before being sent back, with the refund issued within 7 days of acceptance. Return postage is paid by the customer.