Pond Lighting

Lighting has been used in and around ponds for years to convey different moods and effects. Underwater lighting can extend the life and entertainment from a pond well into the night, creating a focal point of both sight and sound for an evening around the barbeque, while subtle lighting can be used to delineate a path or give a lit backdrop.

  1. Do I need lighting in my pond?

Unlike say a pump or filter, a pond’s health and well being does not depend on pond lighting. Lighting will not impact on the biology of the fish and other pond life and will not affect the water quality in a pond.

  1. What are the benefits of lighting a pond?

Lighting is not installed out of necessity, but by choice, benefiting the aesthetics and presentation of your pond after dusk.

Artificial lighting gives us the opportunity to direct light in ways that nature did not intend, shining light upwards out of ponds, bouncing off the underside of bridges or from beneath stepping stones.  Underwater lighting also gives us the opportunity to see fish illuminated from below, watching silhouetted fish darting about in the twilight.

Underwater lighting can be used in a number of  ways to add atmosphere to a pond.  Simple spotlights can be used to cast shadows in the misty water.  These can also usually be used outside a pond as their low wattage bulbs will not overheat and their waterproofing seals make them very weatherproof.

  1. What power options can I choose from?

Lights in and around your pond can be powered in a number of different ways.

    1. 220v underwater lighting. These consist of a single spot light that is supplied on its own base to be positioned within the pond for maximum effect. Like the majority of other underwater lights, interchangeable coloured lenses maybe available to add different moods as required.
    2. Low voltage (12v, 24v) underwater lighting. The vast majority of underwater lights are low voltage as they pose far fewer risks than mains-voltage lights. Unlike submersible pumps, lights cannot be encased in resin to make them water tight but must be accessible for maintenance and bulb changes. This can make sealing them satisfactorily quite problematic, especially when you consider that pondkeeping DIYers will be responsible for resealing them after a bulb change.

A low voltage light system requires a transformer to drop the current down to 12 or 24v. Usually the transformer must be housed indoors in a well ventilated site. However, recent advances have meant that some transformers can now be sited within the pond itself (exploiting the resin-encasing safety measures that have benefited submersible pumps). At least there won’t be any overheating problems for these transformers. Another benefit of low voltage lighting is that the wiring can be carried out tool-free, using clamping systems etc that pinch through the low voltage cable to make contact – something that would be far too risky for mains voltage lighting.

    1. Solar powered lighting.  This type of lighting has many benefits from the point of installation and running costs, as there are no wires and no running costs. They have an integral rechargeable battery that is charged up via the solar panel during the day. At night time a photocell in the light automatically switches the light on (a feature found in many low voltage systems also – see picture). To be most effective, these lights need to be installed in direct sunlight as their night time output is directly related to the power stored in the day. They are not as bright as low voltage lights, providing more of a glow. Solar lighting also has its limitations in the winter months when sunlight and daylength do not work in the rechargeable batteries’ favour.
  1. What light options can I choose from?
    1. Submerged:
  • Single spotlights
  • Multiple lights fixed to the pump
  • Either in white or with coloured lenses
    1. Fountain lights
  • These units illuminate the water as it is ejected through a fountain head. The ejected water that forms the fountain then picks up the light ‘fibre-optic-style’ as it cascades onto the pond.
    1. Floating lights
  • Solar and low voltage options of floating lights are available in various shapes and sizes, including a floating Perspex ball.
  1. What do I need to know before I can buy the right light?

Unlike choosing other electrical pond hardware, the choice of lighting is down to personal taste. The biggest considerations will be the light output you require, the number of lights and the length of cabling required. If choosing low voltage lighting, you will have to plan where the transformer is going to be located as this will determine the lengths of 220v and 12v/24v cable required. From experience, in practice you always seem to use more cable than anticipated so add 20% extra to the planned length when purchasing cable.

  1. Running costs?

Solar powered units will of course have no electrical running costs, with replacement bulbs being the only expense.

Low voltage running costs can be calculated approximately by adding the total wattage of the bulbs in use. This will amount to several pence each day (or night!) for an average pond. The wattage displayed on your transformer will give you the best indication for power consumption of your lights.

Mains voltage lights will be the brightest and most powerful of the 3 options and will consequently consume more power than other lamps on a like-for-like basis.

  1. Will I need anything else?
    1. RCD circuit breaker for safety when using underwater lighting. A circuit breaker should be fitted as standard to the electrical supply of any pond. It may be wise putting the lighting on its own dedicated supply so that if the circuit trips, it doesn’t cause your pump to cut out also.
    2. Additional cable and water proof connectors when using mains (220v) lights, depending on the run of cable required.
  1. What about maintenance?

The most common and regular maintenance carried out on underwater lighting is cleaning the light/lens to remove algae and slime. Be sure to do this when the light is turned off.

  1. Guarantees and lifetime?

Many light units are available with guarantees longer than the statutory 12 months. Replacement bulbs are usually standard halogen-type and are available from most DIY stores.


Illuminfx – new from across the pond.

While I was on an aquatic trade seminar tour in the USA earlier this year, I was fortunate enough to witness a truly innovative pond lighting system which used cutting-edge fibre optic technology to achieve stunning pond effects. Called the Aqualite, this system, offers many benefits over conventional pond lighting systems and deserves a mention all to itself.

What makes the Aqualite so different?

The fibre optic technology allows up to 16 different light fixtures to be driven off just one light bulb. This means that the light box can be remote from the pond, with the fibre-optic cables transmitting the light risk-free into the garden and pond. This means that should it need replacing, only one bulb is required rather than 16 – and all that without getting your hands wet or disturbing your pond.

There is no heat or electricity in the pond and the inconspicuous light apertures at the end of each fibre-optic cable means that they are easy to hide and position in and around the pond – waterfalls are a speciality.

Furthermore, colourwheel technology means that with the flick of a (remote control) switch, white light can be turned into a moving rainbow of colours throughout your pond and garden. This dynamic lighting effect is something that just cannot be achieved with standard pond lighting.

Overall, the Aqualite produces a low-risk, hi-tech moving kaleidoscope of colours – all of which is completely concealed and effortless to control and maintain. Well worth a look!

Kill blanketweed and string algae.