This 200lph solar air pump is our bestselling model. It boasts twin air line and air stones to generate up to 200 litres of vital oxygen per hour to your precious fish. This solar pump has zero running costs and works best in sunnier weather just when your pond's inhabitants need it most!air pumps are essential for the health of your fish especially in the summer when oxygen levels are depleted. Additional air leads to additional water circulation and a healthier pond.the pondxpert solarair 200 is perfectly suited for the following ponds br • no fish 1,500 litres 330 gallons br • fish 1,100 litres 240 gallons br • koi 500 litres 110 gallonsaccessories included with the solarair 200 br • 2 x 4mm air line 2m br • 2 x air stonesolar powered the solarair air pumps are powered by the sun and contribute a good flow of air into the pond. No electrical installation required!please note this item works in direct sunlight only. If you want your solar pump to work when conditions aren't sunny then we have a leading range of battery back up solar oxygenators to choose from.