CHRIS’ GUIDE TO CHOOSING A POND PUMP
1. Is the pond in full sun or in the shade? If the pond is in a sunnier area, it will generally be better for plant growth, but less so for certain fish. Sunnier areas will generally require more filtration to prevent the water turning green.
2. What size pond pump will you need? Divide the capacity of your pond (L) by 2 to obtain the average flow required in litres per hour. Then divide the result by 60 to find the average flow in litres per minute.* E.g. A 6000L pond will require 3000 L/hr flow (50 L/min). *Note this is only to be used as a guide. Other factors such as the amount of fish/plants in your pond will affect the result. If the pump is too large for the pond, it will be noisy, slow down the rate of plant growth and aerate the water excessively. It will also be detrimental to any fish living in the pond. On the other hand, if the pump is too small for the pond, then there will be patches of stale water, leading to algae growth, bad smells and will not provide enough oxygen for fish.
3. Which of the following best suits your pond?
a) Heavily planted with little or no fish Will not need as large a flow - Divide total capacity of your pond by 2.5 to obtain average flow required. E.g. 6000L pond will require 2400 L/hr (40 L/min).
b) Even mix of plants and fish Will require a standard level of flow - Divide total capacity of your pond by 2 to obtain aver average flow required. E.g. 6000L pond will require 3000 L/hr (50 L/min).
c) Little or no plants with plenty of fish Will require a higher flow rate - Divide total capacity of your pond by 1.5 to obtain average flow required. E.g. 6000L pond will require 4000 L/hr (67 L/min).
4. Do you want to have a water feature/fountain or waterfall? Waterfall or fountain applications will generally require higher head and flow rate. Therefore, the typical circulation pond pump may not be suitable.
5. Will the pump be submerged in the pond or kept above ground? some pond pumps can be submerged in the pond or installed above ground.
6. Do you want a 240V or low voltage pump? Low voltage pond pumps are most often used where 240V mains power is a distance away from the pond.
7. How energy efficient is the pump? A pump with lower power consumption will be most energy efficient at a given flow rate. Compare the power of the pump at its maximum flow (in W).
8. What about filtration? Don’t forget that if a pond is to hold fish, a gravity or pressurised filter will be required. Therefore, allowances must be made for the filter’s required flow rate. Filtration also prevents the pond water from turning green. An optimal system should contain both biological and UV filter to maximise the management of the water system.