Which pond pump should I choose?

How to choose the right pond pump and why is it important to choose the right pond equipment?

Koi keeping is so enthralling and challenging because it puts demands on us from so many different disciplines, and to be successful, we need to master them all. We need to understand biology, chemistry, physics and have all the practical DIY skills to match – including those of a carpenter, landscaper, electrician and plumber. In fact, it could be argued that it is these extra demands and challenges that are a significant appeal and attraction in themselves – before we even get to buy a single koi. It’s essential that we get every aspect of the pond right – including the choice and installation of the pond hardware as it will affect our enjoyment and success at koi keeping in many different ways.

You want the best pump for your garden pond? see these pumps

1. Life support. Our choice of equipment must support and maintain our koi’s environment 24/7. If it fails or lets us down, then our koi will immediately be put at risk.

2. Maintenance. Unless you’re one of the very few that enjoys hands-on pond maintenance, an unwise choice of pond hardware can sentence you to extra maintenance over many years.

3. Expense. I’ve heard it said – ‘buy it cheap – buy it twice’. This applies if you buy pond equipment incorrectly or below the specification you really need. Make the purchase decision on the value that you are getting, rather than just the price you are paying.

4. Running costs. Hopefully, your purchase will be a wise one and one that lasts for many years. Over that time, if it has running costs, they will prove to be a significant factor. Choose wisely and the hardware could pay for itself in the money that it saves you in lower running costs.

5. Ease of use. You might be tempted to buy on a good price and even specification – but how easy is it to use? It’s likely you’ll be tempted not to use it if it’s too difficult to use.

What’s the job of a pump in a pond set-up?

A good pump is one that is quiet, reliable and one that can almost be forgotten once installed. Often referred to as the heart of the pond, any pond pump (like our heart), must perform the most reliable function of a koi pond system. Because of its partnership with a pond filter, if a problem develops with your pump, then a problem is likely to follow in your pond’s balance.

Pumps – performing many roles.

As koi ponds are generally stocked with fish above what is natural and self sustaining, the balance of the pond and ultimately the health of your koi are completely reliant on your filter system, which in turn must be fed continuously by your pump. Besides the obvious tasks of trapping or removing solids, a filter also performs the function of breaking down toxic waste produced by your koi. These beneficial bacteria require a steady flow of water to supply them with food and aerated water and to remove their by-products. Should your pump malfunction, or its performance be reduced, then the colony of bacteria would deteriorate leading to a similar deterioration in your water quality. Whenever a pond does experience pump problems, be they a complete breakdown or a drop in performance, then the vital role played by a pump is self-evident, when koi can be seen sulking or gasping at the surface.

An additional function for the pond’s work horse is to circulate water through an ultraviolet clarifier. These algae-busting add-ons must be pump-fed to ensure that the unit runs at full-bore. Even though a UVC is not 100% efficient in flocculating all single celled algae in their first pass, their long-term relationship with a pump is essential for clearing green water.

Pumps can also be installed with a dual role of both water circulation and aeration, through the operation of a venturi. This is most applicable in a gravity-fed filtration system, where the filter chambers are installed alongside the pond, running at the same level as the pond. In the final chamber, where the water is at its cleanest, a submersible pump can return the water to the pond through the pond wall via a venturi. The pressure provided by the pump causes air to be drawn into the flow through the venturi, leading to Jacuzzi-like aeration of the upper layers of the pond. If you want a venturi, check that your choice of pump will have the power required to drive one effectively.

Besides performing the less glamorous functions of a pond, the pump can also perform aesthetic functions.

Although not as common in koi ponds as garden ponds, fountains can add another dimension to the life of a pond. With many different types of jet and fountain head to choose from, then there should be a fountain to satisfy your taste.

A more realistic role for a pump is to provide the life to a waterfall. More common in a koi pond than a fountain because of the need to use some of the spoil from the excavation as a feature, or to incorporate a pump-fed filter (which will in turn feed a waterfall). Either way, a waterfall requires a larger pump than if a waterfall had not been installed.

Are there different types of pump?

There are essentially two types of pond pump available to the koi keeper – the external or surface-mounted pump and the submersible pump.

1. External pumps.

External pumps are sited outside of the pond. They should not get wet and are ideally installed in a small protective pump house. Water is sucked from the pond (or filter) through a rigid suction pipe. These pumps are often referred to as swimming pool pumps and are better suited to larger, more specialist situations where above-average turnover of pond water is required. They are essential if a sand pressure filter is required as part of the filter system as they are capable of pumping to high pressures.

2. Submersible pumps.

Submersible or internal pond pumps are by far the most popular pond pump. They are extremely versatile, being available in a range of sizes to suit most koi pond applications. They are very straightforward to install and having been developed in a very demanding market are sold with lengthy guarantees. All of the electric components within the body of a submersible pump are safely encased in hard resin which is itself retained in a robust and water-tight pump body.

Kill blanketweed and string algae.