Suitable for up to 7000 litres of water, 25 Watt.These aeration pumps have been made especially for Velda. They combine a tremendous air yield with excellent quality and lifetime. The pumps are universally usable and are frequently applied for the aeration of ponds, however, they are also very suitable for aquaria. The diameter of the hose liner is 8 mm. Silenta Pro aeration pumps are supplied including a ‘Giant’ aeration stone and 5 m of reinforced aeration hose of 8 mm. Owing to the high pressure several aeration stones can be connected at the same time.To obtain a good biological environment, in which fish and plants thrive excellently, it is necessary for many garden ponds to apply aeration in the pond water. Aeration produces oxygen and keeps water moving, thus allowing optimum bacterial development and a correct equilibrium in the pond.Summer -When the water temperature rises, lack of oxygen often occurs. The fish will swim to the surface to gasp for air. And when you remove algae, you take away an important source of oxygen too. Aeration of the pond brings relief in that case. The bubbles of air will release oxygen and remove harmful gasses from the water.Winter -When in winter the pond freezes over, fish mortality by suffocation often occurs. However, you should never smash a hole in the ice, because the vibrations are harmful to your fish. Aeration of the water is a better solution. The air bubbles will keep the pond ice-free and oxygen-rich.