Water features such as a pond can create a peaceful haven in the garden. Imagine flourishing plant life, rare wild birds and exotic fish gracing your backyard. An idyllic place to spend a sun-kissed Sunday afternoon, if you ask us.

But, if you want to keep the plant and fish life in your pond healthy, it is essential you do not allow your pond water to become stagnant.

Stagnant water is an incubator for bacteria and once bacteria starts to multiply and accumulate, it will quickly (in a matter of hours) kill off your beloved pond life.

So, how do you keep the water in your pond circulating? Well, to do that, you will need to purchase and install a pond pump.

Now, if this is your first pond, you might be confused by the wide variety of pond pumps available. 10m Head Height Pond Pump, Max Flow Pond Pump, 10,000L Pond Pump - it can all get very confusing.

So, to make your selection process easier, here are the eight things you need to know before choosing a pond pump.

1. Calculate the Water Circulation Required

All of the water in your pond should be circulated once per hour. This means all the water is circulated 24 times a day, which is good for the plants, fish and filters in your pond.

Flow rate is the term used to describe the amount of water flowing through your pump over a period of time. In the UK, flow rate is calculated in Litres per Minute/LPM (not Gallons per Hour/GPH, which is the US calculation).

To determine what flow rate you need from your pond pump, simply divide the total water capacity of your pond by 60. For example:

With a 7000 litre pond, simply divide 7000 by 60 = 116.6. In this case, you need a pump with a flow rate above 116.6/LPM.

2. Additional Water Volume for Waterfalls

Waterfalls are an impressive addition to a pond, as people like the sound of running water.

However, you will need to work out the volume of water needed to create an impressive waterfall.

You need about 250-350 litres of water per hour of flow per inch (2.5cm). A waterfall with a wide lip will use more water than one with a narrow overflow edge. The ideal height for your waterfall is between 40cm (16 inches) and 90cm (36 inches).

3. Buy a Pond Pump with a Guarantee

Pond pumps live a tough life. Not only are they submerged in icy cold water but they also have to deal with all the debris, dirt and bacteria that will no doubt find its way into your pond.

As such, you want a pond pump that is built to deal with the toughest conditions. The easiest way to figure out which pond pumps are a sturdy, quality build (and which are not) is to look for a two-year guarantee.

If it comes with a two-year guarantee, you can rest assured that it will last way beyond that.

4. 24 Hour Pumping Capability

If you have fish, a pond pump must be able to run 24 hours a day, 365 days a year, without fail. A solar-powered pond pump is not a practical solution. If it fails, bacteria will multiply quickly and you will only have a short period of time to save your fish.

Always buy a pond pump with 24-hour pumping capability if tending to fish.

5. Always Have a Back-Up Pump Available

It’s always best to have two pond pumps. One that is running continuously and another as a backup if the first one fails.

Bacteria can multiply so quickly that even waiting 24 hours for a new pump to arrive could seriously harm the short and long term health of your fish.

Plus, your pump will fail one day. Would you rather have a pump ready at hand? Or would you rather have to pay next day delivery to ensure it arrives quickly enough to save your fish? To us, it’s a no brainer.

6. Understand Head Height

The head height is another key specification you'll need to know when buying a water feature pump. The head height refers to the distance between the water level and the height you want to pump water.

This is a particularly important specification if you have a water fountain or waterfall, as you will need to maintain a certain amount of pressure to ensure the water can be pushed far enough upwards to reach the outlet.

Head height can be quite complicated, so we’ve produced a dedicated guide here.

7. Calculate Running Costs

You will need to think about the running costs too, which you can calculate yourself. The wattage used by the pump is usually stated on its box. If not, look for the amps used on the label attached to the body pump itself. You can convert amps to watts by multiplying amps x volts. For example, if your amp is .2 and your voltage is 220, then your pump runs on 44 watts.

This also means the pump will consume 44 divided by 1000 units of electricity per hour (1 kWhr = 1 unit)

To work out the costs, use the following formula:

Cost per year = "Y"
Pump power = "W" Watts
Pump runs "H" hours per day
Cost per unit of power ="C" in pence
Y=[W/1000 x Hx365 x C/100] in pounds a year.

8. Double Check the Cable Length

It may seem a tad bit stupid, but you should double-check the cable length of the pond pump. The vast majority of pond pumps come with a 10 to 12-metre power cable. If your pump is further than 10 metres from a power outlet, then you might need to purchase an extension cord.

You should also check if the cable is for commercial or domestic set-up. If it’s for commercial use, it will generally be designed for connecting to a generator. This will be quite impractical for the average garden pond.

Free Advice

If you’re struggling with advice regarding pond pump sizing, ring our dedicated experts on 0800 112 3134 or 0333 577 3134. We’re open Monday to Friday 07:00 - 17:30 and Saturday 08:30 - 12:30