Adding a pump gives the pond a heart able to drive the circulation of water through filters and UV clarifiers, fountains and waterfalls, giving the whole water feature a new dynamic dimension while helping maintain a healthy environment at the same time. A visit to the local pond suppliers or a quick search online will soon reveal a bewildering array of makes, models and sizes – and it can often seem a little difficult knowing where to start with all the types on offer. Fortunately, if you have a pretty good idea of what you want your pump to do, then making the right selection need not be too daunting.
Types of Pump
There are three main types of pump for the garden pond, each with its own particular characteristics. Small “feature” pumps are intended to drive bubble fountains and ornamental pebble pools, most coming with a fountain head already attached and for the right application; they provide a relatively cheap way to bring moving water to the garden. While they are perfect for the likes of a half-barrel water feature on a patio, their capacity is usually too low to be of much use in full-size garden ponds. To deal with these larger quantities of water, something bigger is needed – the traditional pond pump being a scaled-up and more robust version, typically with an enlarged pre-filter to keep solid material from damaging the mechanism. This type of pump is ideal for most garden ponds and the perfect choice for fountains – most come with a selection of suitable jets in the box – since the pre-filter prevents the nozzle holes from being clogged.
The last of the three – called “solids handling pumps” because of their ability to allow small particles through without the risk of damage to their workings – were principally developed to meet the needs of bio-filters, which require relatively powerful pumps. Their design has brought greater reliability and lower maintenance to the water garden, making them ideal for use in waterfalls too – though not, obviously, for fountains.
Sizing the Pump
Having decided what sort of pump to buy, the next step is to consider how big it needs to be. Most of the common problems – and disappointments – with moving water stem from the wrong size pump being used. For a waterfall a handy rule of thumb is to look for a capacity of around 150 litres of water per hour for every one centimetre width of waterfall – a 20cm wide waterfall needing a 3000 litre per hour pump, for instance. To produce an impressive fountain, rather than a feeble trickle, check how high the pump can be expected to drive the water; all other things being equal, the greater the height, the better the display. If the pump is primarily to be used to feed a filter, bear in mind that ideally the entire volume of water in the pond should pass through the filter every 90 minutes or so – with a fairly accurate idea of the amount of water your pond holds, the rest of the calculation is easy.
Of course, many pumps feed filters, which then pour into waterfalls and large numbers of ponds have waterfalls and fountains – though it is seldom a good idea to use one pump to drive both. If you do want a cascade effect and a fountain, buy separate pumps. A common solution which many pond-keepers have adopted is to use a solids handling pump to run a combined waterfall/filtration system 24 hours a day and a suitably sized ordinary one to drive a fountain – which can be switched off at night or when not required.
Light and Power
Most pond pumps require an electrical supply, either mains or low voltage and it is clearly necessary to install them safely – ideally with the advice of a competent electrician – as water and electricity are not a good mix at the best of times. Alternatively, you might wish to consider one of a growing number of solar powered pumps which have also become available – though for obvious reasons, they are generally not suitable for uses where round the clock running is necessary, such as filtration for a fish pond. If pond lighting is also to be installed, now can be a good time to think about doing that too, particularly since many of the pump manufacturers, including Heissner, Hozelock and Oase, offer pumps with clever lighting effects built-in.
With the recent advances in pump reliability and performance, there has never been a better time to add moving water to the pond. Equipping your water garden with a pump improves water quality, aerating, mixing and circulating, providing at the same time the opportunity to filter and clarify for a vastly improved pond environment. It also lets the whole thing come alive with the sight and sound of running water – the real reason many people build a pond in the first place!