Kockney Koi Supersoft 4mm Clear Silicone Airline – 30m & 100m

Kockney Koi Supersoft Clear Silicone Airline – 4mm

Connect compatible air pumps, small manifolds and air stones with Kockney Koi Supersoft clear silicone airline. This flexible tube has a 4mm internal diameter and a 6mm outside diameter. Choose a complete 30m or 100m roll, then cut the individual runs to suit your pond, filter or aquarium aeration layout. The listing supplies airline only; pumps, valves, connectors and air stones are separate items.

The roll length is the total amount of tubing supplied, not a recommended distance between an air pump and a diffuser. A long coil is useful for several short branches, replacements or a larger installation with multiple outlets. The right length and bore for each branch still depend on the pump, the diffuser, the water depth and the way the system is arranged.

Choose your roll

Option	Internal diameter	Outside diameter	Colour
30m roll	4mm	6mm	Clear
100m roll	4mm	6mm	Clear

Measure all the routes you intend to connect and allow enough slack to reach the equipment comfortably. Include the distance from the manifold to the pond edge, down to the diffuser and around any obstacles. Avoid leaving a tight line that pulls on a small plastic outlet whenever the pump or air stone is moved for cleaning.

Check the fitting size before ordering

The 4mm measurement refers to the bore inside the tube. The outside measurement is 6mm. This matters when comparing a push-on airline barb with a fitting described by its outside tube size. A 6mm push-fit connector is not automatically equivalent to a barb intended for 4mm-bore airline. Check the connection design as well as its stated number.

Our Kockney Koi 4mm airline connectors offer suitable options for joining and arranging compatible small-bore branches. Choose the connector shape to suit the job, and remember that a tee divides a route but does not independently regulate each branch. Use the appropriate air control valve where individual adjustment is needed.

A large pond air pump may have an outlet or recommended distribution pipe much bigger than 4mm. Do not assume this tube should be attached directly to every pump simply because it is sold for pond aeration. Retain the manufacturer’s specified main connection and distribution arrangement, then use smaller branches only where the equipment is designed for them.

Plan for reliable airflow

Keep individual runs as short and direct as practical, with broad bends rather than tight folds. Air has to travel through the hose and overcome the resistance of the diffuser and the water above it. A weak stream of bubbles can therefore have several causes: a kink, a leaking connection, a dirty stone, an unsuitable branch layout or a pump working beyond its useful operating conditions.

Where several air stones share one supply, the shortest or least restrictive route may receive more air. Arrange the branches sensibly and balance them with suitable air valves if required. Do not close every outlet on a running pump. Follow the pump’s instructions for any bypass or pressure-relief provision, particularly when changing the number of diffusers in service.

Routing and installation

Uncoil the length you need before cutting and check the route with the equipment in its normal position. Make a clean, square cut using a suitable sharp tool, keeping fingers clear of the blade. Fit the tube to the correct connector as directed by the equipment manufacturer. An end that is split, hardened or stretched from an old fitting may need trimming or replacement.

Keep the line clear of sharp coping, closing lids and places where it could be stepped on or pinched. Support it where necessary without crushing the bore. Leave enough access to remove an air stone for cleaning without dragging the pump or pulling electrical equipment towards the water. Protect the pump according to its own instructions; flexible airline does not make an indoor-rated pump weatherproof.

Check the air pump’s guidance on positioning above water level and preventing water from travelling back towards it when switched off. Where a non-return valve is specified, choose the correct size, fit it in the marked flow direction and inspect it periodically. A valve needs to be suitable for the installation; it should not be treated as a reason to ignore the pump’s positioning instructions.

When sinking airline is a better choice

This is ordinary clear silicone airline, not a weighted sinking hose. If you want the route to lie discreetly along the pond floor, compare our standard sinking airline or Evolution Aqua heavy-duty sinking airline. Check the bore and connector requirements when changing between products.

For a reinforced alternative, see black braided airline. That hose also does not sink, so choose it for its construction and suitable connection size rather than expecting it to remain on the pond bottom. The best choice depends on the route and equipment, not simply the colour of the tube.

Routine checks and maintenance

After connecting the line, run the system and check every branch for the expected bubble pattern. Inspect joints for looseness and check bends for flattening. If airflow changes later, work through the route methodically before replacing the pump: hose condition, valves, connectors and diffuser cleanliness are all worth checking. Keep spare tube clean and loosely coiled, ready for future maintenance.