Aeration in a fish pond is an essential part of the eco system. By providing adequate air, the water remains rich in oxygen that benefits the fish and gives them the healthiest environment to live in. The Pisces Sinking Airline has been designed to sit along the natural contour of the pond side, eliminating the need for weights to keep it in place. Unlike standard airline, the tubing is make of thicker and heavier material, making it easier to sink and sit in place. It is also resistant to UV light exposure and is tough external material makes it resistant to kinks and damage The airline also blends in with the colour of the pond liner and lays discreetly in the water and along the base of the pond when connected to a robust airstone. Specifications Internal Diameters Available -4mm Available as 1m lengths - add the metres you require into the quantity box. Your order will arrive as 1 continious length eg for 12 metres put 12 into quantity box