Evolution aquarsquos range of uv clarifiers consists of the evo30 30 watt uv bulb evo55 55 watt uv bulb and evo110 2 x 55 watt uv bulbr the evo30 is suitable for ponds up to 30 000 litres the evo55 is suitable for ponds up to 55 000 litres and the evo110 is suitable for ponds up to 75 000 litres there are factors that can affect this in particular surface area of your pond the amount of shade given to your pond and stocking levels if in doubt speak to us at warehouse aquatics for