All About Outdoor Fish Pond Pumps | All About Fish Pond Water Pumps

Today I would like to talk about fish pond water pumps and the basic information you need to know in determining which pond pump suits your requirements.

The water garden market is flooded with fish pond pumps from all four corners of the globe. In recent years the expansion of the Chinese economy has led to an influx of inferior, less reliable but cheaper to buy submersible fish pond pumps and larger external fish pond pumps.

At first these fish pond pumps may seem like a real bargain but they are not all they are cracked up to be! The following explanations will help you to gain a better understanding of pond pump basics.

Pumps ... What does maximum flow mean?

Maximum flow is the absolute maximum water the pump can handle. However it is only able to pump this amount with no pipe attached to it. It is an impractical indication of pump usefulness.

What does Pond Pump maximum head mean?

This bit of information means at that head or height difference between the water surface and the waterfall the flow from the pump will be 0 litres per hour - i.e. at pond pump max head there is zero flow. Many models will show a maximum pond pump head height. This is a fancy word for what pressure can the pump develop. In other words how high can it pump.
This information should be ignored or used to compare one pump to another. This information has mislead many people into buying wrongly specified fish pond pumps. It is important to know how much water the pump can handle at different practical heads or height differences between the water surface and the waterfall inlet for example rather than the maximum pond pump head.

Is it best to buy Cheap Fish Pond Pumps?

NO is the short answer here ... The majority of retailers who sell cheap fish pond pumps will never mention the advantages of low power consumption pumps yet this is a very important part of the purchasing decision. I would go as far as to say that the best fish pond pumps may cost more but invariably have lower running costs.

How do I know how much water my pump must handle?

As a basic rule of thumb a pump should pump the total volume of the pond every 2 hours. In this way the contents of the pond are circulated 12 times a day. At this flow rate there is a good balance between the needs of plants, fish and the biofilter in a pond system. You may want to pump more than this if you want an impressive waterfall effect.
A pond of volume 1321 US gallon (5,000 litres) would be happy having a pump flow rate between 528 gph - 1057 gph (2000 lph to 4000 lph). A pond of volume 528 US Gallon (2000 litres) would be happy having a flow rate between 185 gph to 425 gph (700 lph to 1600 lph).
The important point is to get the flow rate somewhere between one third and about two thirds of the pond volume for a good balance. What is more important is that if your pond is say 264 gph (1000 litres) you certainly do not need a pump that can do 1321 gph (5000 lph).

How can I tell if a pump is made for use in a garden pond environment?

Fish pond water pumps are designed to operate in harsh outdoor environments. In practice this means the water in which they reside becomes polluted. Foreign objects find their way into the pump moving parts and can do damage if the pump is not designed to withstand these rigors. Outdoor fish pond pumps have been designed to withstand this type of environment.
It is illegal to sell outside fish pond pumps unless there is at least 10 metres of 3 core cable attached to it. The box and if not the box the label on the pump itself will indicate whether or not the pump is for indoor or outdoor use ( a small sign showing picture of house with arrow pointing into the house indicates for indoor use only). The pump will have 2 or 3 year guarantee period. If any of these are missing do not buy the pump for use in a pond.

Why is a guarantee so damn important?

A 2 or more years guarantee tells the customer especially when it comes to pond pumps that the design is good, the performance good, and that the manufacturer stands behind his products.
A pond is a very harsh environment in which a pump has to run 24 hours a day 365 days a year. When you see a 2 or more years guarantee on a pump you can buy with total confidence. Beware of Sump pumps. These pumps are powerful and large - they stand upright and are thus easily recognized. Sump pumps are designed to run for a certain amount of hours and since they are primarily designed for intermittent running their life span can be considerably shortened when run continuously in a pond.

How to select the Right Fish Pond Pumps

Selecting the correct pump is critically important. Apart from doing the job you want it will last you a long time and running costs will be very low. If you want a waterfall and no fountain then make your selection from fish pond water pumps which do not need a sponge on the suction side of the pump. This saves a lot of maintenance. Do ask us for advice if you are not sure.
You can spot outdoor fish pond pumps very easily. They will have have 10 metres of 3 core cable and the box will tend to be larger. There will be a guarantee of at least 2 years - DO NOT buy 1 yr. guarantee pumps for ponds. They do not last. You need to specify how much water in litres per hour (GPH) you want to pump and to what height this quantity must be pumped.

Pumps and Fountains ... I must have a fountain in my pond

If you need to run a fountain in your pond it normally makes good sense to select a pump that comes with these fittings.
If you buy the fountain attachment later it may be expensive. On the other hand there are some very impressive fountains which might appeal to you. If you want to run both a waterfall and a fountain make sure your pump is powerful enough. You must run the pump with the sponge in the suction to prevent the holes in the fountain blocking with debris. The bell fountain is a very popular design.

Pumps and Waterfalls ... Do I need a waterfall?

It is a good idea to have a waterfall for the following reasons: To hear running water, to add character to your pond feature, to add oxygen to the water for the benefit of the fish and the biofilter and to use the soil that came out of the ground when you installed the pond.
A waterfall with a wide lip will need more water than one with a narrow lip to create a good effect. In my experience the fiber glass rock-like waterfalls are perfect for most garden ponds and are well designed to handle the appropriate water flow for the size of the waterfall itself. Very few garden ponds benefit from a waterfall as high as 1 meter and even this is probably too high unless a cascade effect rather than a fall effect is required. An ideal height for a waterfall is between 40 cm and 60 cm.

Pipes and Fittings ... What pipe and fittings are best to use?

Until recently it was only possible to get clear hose or normal hose pipe or to use rigid PVC hose. All these suffered for major disadvantages. Transparent hose and garden hose pipe kink easily. Rigid pipes need expert fitting and are difficult from maintenance viewpoint. It is now possible to buy ribbed hose.
Ribbed hose pipe does not kink and is easy to use and very versatile if used with EasiFitt connections. Do spend a bit more on fittings and hose to reduce your pond keeping hassles. Avoid using jubilee clips which rust and become difficult to remove for maintenance. If you do use clear hose make sure you do not have kinks in the line. This will severely restrict flow from your pump. Avoid sharp bends and minimize the number of connections in the lines.

Pipes and Fittings ... What pipe sizes do i use in connecting pumps, biofilters and UV Systems?

Always use the largest diameter pipe you can consistent with fittings on the pump or other piece of equipment. The reason is that larger diameter pipe interferes less with the flow rate from the pump.
If a pump is supplied with a 20mm outlet then use 20mm pipe. If the pipe is to be very long, say 10 metres then it would be useful to install a reducer to increase the pipe size from 20mm to say 25mm. What is important is to reduce pipe length and increase pipe diameter to get the best out of your pump. Do not use 13mm fittings and pipe except on very smalls pumps.