All types of nets for fish farming

Solid nets that you can rely on

Knox have been making nets for fish farmers worldwide since the industry’s beginnings, producing a range of customised cage nets, bird nets, predator solutions, sweep and sampling nets. In conjunction with our partners, Garware-Wall Ropes, we now also supply lice shields, treatment tarpaulins and wrasse hides.

We are the Scottish distributor for LiftUp mortality extraction systems and exclusively use Steen-Hansen antifoulant and polish coatings on our nets.

Cage nets

Cage type, site conditions and user preferences are all taken into account when choosing the ideal rigging and netting specification for your cage pen, whether using traditional stabilised knotless nylon or STAR netting from GWRL, which makes in situ cleaning easier due to the smoother surface. A further recommended netting for growing fish is GWRL’s Sapphire Seal Pro, with a polymer core and stiffness enhanced by hot waxes injected during braiding. To ensure that water exchange is maximised, nets are roped with the mesh square, whether first feeder size or the heaviest weights required offshore. Build up your specification with input from our sales team - three of whom are ex-fish farmers and think practically.

Bird nets

Bird nets to protect the surface of the cage are produced from polythene, nylon or a specialist mix netting, in mesh ranging from 50mm to 300mm square. Chafer panels to protect the net from the support are often added in the centre, using a heavy duty 25mm mesh netting. Recent advances have seen high poles used to raise top nets from the surface, with side panels incorporated into the design.

Predator control

Nets for effective predator control below the surface can consist of panels to surround one or a complete group of cages or can be complete with bases, produced from nylon or p.e. netting.

Rather than surround the cage net, why not rope an anti-predator base to the net? Sapphire Ultracore, developed by GWRL, is a knotted high density p.e. netting with a core enhanced by marine grade fine stainless steel wires and can be incorporated as an anti-predator base on cage nets, frequently covering both the base of the net and up to 6m of walls.

Other nets

We produce a wide range of other nets for practical use on fish farms: sweep nets incorporating floats at the top and leadline on the base; mortality baskets with a s/s frame made by our own engineers and either 15 or 25mm mesh; small box nets for sampling purposes and brailer nets, all designed and produced to suit your requirements.

Call us to discuss any ideas and we will translate them into practical products.

Fish health

Non-chemical products for better fish health are being continually developed and improved, in conjunction with GWRL. The robust and porous woven X12 material forms a barrier between the cage collar and net to exclude lice larvae. It can be tubular or overlapping, with monitoring showing better oxygen exchange than with standard polyester. Wrasse hides or even combination hides for all cleaner fish can be strung across the cage and are available in lengths to suit.

When chemical treatments are considered, we supply wedge and cone-shaped tarpaulins, and will repair and renovate as required.


If the addition of antifoulant coating to a cage net is part of your farm’s fouling management strategy, then you can rely on Knox to treat your net purchase before it leaves our factory. We have exclusive UK use of well-proven treatments from Steen-Hansen, including the copper-based AquaNet and biocide-free NetCoating or polish, which protects the net fibres during the washing process. All nets are fully dried before being despatched.


As Scottish and Irish distributor of the popular Norwegian LiftUp systems, we hold stock in Ayrshire of the most popular mortality extraction systems and of all major components, ensuring a timely supply.