Opaque Polyethylene Tubing 1/4" - Sold by the Metre

Opaque polyethylene tubing 1/4"

Semi-rigid polyethylene tubing, 1/4" (6,35 mm) outside diameter, sold by the metre. Opaque version. Compatible with all 1/4" push-fit quick-connect fittings, John Guest, DMfit and equivalents.

Buying by the metre means ordering exactly the length the job needs, with no leftover reel and no unusable offcut.

Why opacity matters

This is the defining feature of this tubing, and it is anything but cosmetic.

Opaque tubing lets no light through. No light means no photosynthesis, therefore no algae growth inside the tube. On translucent tubing exposed to daylight, a green film can appear within weeks, particularly on low-flow or idle sections.

That makes opaque the default choice for any run exposed to light: surface-mounted runs, outdoor routing, glazed plant rooms, or installations left unused for long periods, holiday homes, occasional draw-off points.

Opaque or black: what's the difference

As far as light goes, none: both block radiation.

The difference is identification. On a multi-line installation, a distinct colour, black, blue, red, white, makes it possible to identify each circuit at a glance: raw water, treated water, drain, tank return.

Opaque is the neutral choice: it provides the anti-algae protection without imposing a colour code, which suits single-line installations or assemblies where visual discretion comes first.

Where to use it

On reverse osmosis systems, feed, product line, drain line, tank connection, on water coolers, American fridges, ice machines, and on any water treatment installation using 1/4" quick-connect fittings.

Fitting

Cut the tube square with a tube cutter. An angled cut, or one crushed with pliers, stops the fitting's O-ring bearing evenly, the first cause of leaks on this type of connection.

Push fully home into the fitting, then pull lightly to check engagement. Keep a generous bend radius: tightly bent tubing goes oval, loses usable bore and fatigues at the bend.

Watch the diameter

1/4" imperial (6,35 mm) and 6 mm metric are close but not interchangeable. Metric tubing is not gripped correctly by the collet of an imperial fitting and leaks under pressure. Check the standard of your fittings before ordering.