Swimming pool lights – underwater lighting improved

swimming pool lights

Things to ponder before buying

There are various things you need to think about before you get down to the nitty-gritty of buying swimming pool lights. One of the first things that should cross your mind is what type of use your pool will get; is it a place intended primarily for fitness, where customers or family members will swim regularly, or is it more of a relaxation area? These purposes need not be mutually exclusive, but the bias may help you decide what type of lighting you’ll buy.

Safety considerations are also bound to come into play. What type of peripheral lighting is best, and if you’re buying for a commercial swimming pool or spa, are there any legal requirements to be met? The shape and size of the pool will also play a part in the amount of lights you buy, and what colour light they emit. Having pondered all of these things, you can cast any idea of hard and fast rules aside! There are effective ways to light a pool, and there are ways to stay safe, but there is also a significant element of subjectivity—how do you want your pool to look?

Does the size of the pool affect your choice of lighting?

To some extent, yes, if you’re buying for a large public swimming baths or a fitness centre there will be a requirement for high levels of uniformity along the length of the pool, which often means multiple lights with a white output. However, for small to medium-sized pools more commonly installed at homes, hotels, and spas, a single light is frequently enough to illuminate the whole pool.

The light is usually recessed and wall-mounted at the deep end of the pool, which enables a more even spread of light. Placing a light at the centre of a pool typically creates a triangular effect with darkened corners, so this will only usually be done if further lights are to be installed.

It’s worth bearing in mind that coloured lights do not have the same coverage though water as a white light, which is why white lights are always preferred in scenarios where safety considerations dominate, e.g. a public swimming baths. The travel of light through water even varies between colours. The surface colour of the pool is another factor in the effectiveness of your selected lights, with paler colours reflecting the light and increasing its range. Dark surfaces will conversely absorb light, which may result in you requiring more lights to achieve your aims!

Are there any health and safety requirements to consider when lighting a swimming pool?

There are no specific laws pertaining to swimming pool health and safety, other than an obligation to comply with legislation under the Health and Safety at Work etc Act 1974.

One useful resource from the non-departmental Health and Safety Executive makes several references to pool lighting, and is available in the form of a free download: Managing health and safety in swimming pools.

What types of lamp have traditionally been used in swimming baths and pools?

Incandescent and halogen lights were always the traditional choice of underwater lamp in public swimming baths and pools, and they’re still available. Their advantages mostly lie in being inexpensive, and in delivering a consistent output of light through their whole lifespan.

Halogen lights are the bright underwater pool light that many people remember and expect in a swimming pool, and they’re great for their ‘continuous spectrum’, which makes them reliable for rendition of colour (a property of all forms of incandescent light).

Modern-day swimming pool lights — the advantages

There are a couple of contemporary solutions to swimming pool lighting: fibre optic and LED.

Fibre optic lights can create great colour-changing effects in a pool or spa, and they are easy to install and maintain. However, their vibrant glow is often considered too weak for anything other than decorational mood lighting, and their initial cost is greater than LED.

LED lights are generally between 70-90% more energy efficient than original incandescent and halogen light forms, and, significantly in pool lighting, they last for a near eternity! An incandescent lamp might only have a lifespan of 1,000 hours, or 2,000 hours for halogen, whereas LEDs tend to boast longevity of between 20,000 to 50,000 hours.

An estimate of potential savings in running LED pool lights against a halogen equivalent would work out approximately as follows:

  • 18W LED @ 10 hours a day for 1 year = £9.85
  • 100W halogen @ 10 hours a day for 1 year = £54.75
  • 300W halogen @ 10 hours a day for 1 year = £164.25

(Rate based on 15 pence per kWh)

Aside from the great money-saving potential of installing LEDs, one of the other great advantages lies in the flexibility they allow in design. In swimming pool lights this tends to manifest itself in a wide choice of vivid colours and effects, with built in micro-controllers endlessly blending individual red, green, and blue LEDs in more sophisticated models.

Colour changing swimming pool lightYour pool can be simply lit with a bright white light, or for easy creation of ambience you might opt for the soothing effect of a lamp. But if you’re looking to put on more of a show, your underwater lights can be imbued with an ever-shifting rainbow of colours using various styles of transition. Other spectacular pool lights ideas include:


  • A Slow-fading 18W LED PAR56 Swimming Pool Light that gradually cycles through colour using RGB LEDs.
  • A Switch-start 18W LED PAR56 Swimming Pool Light that enables you to pre-set colour output from its light switch.
  • A Remote-controlled 18W LED PAR56 Swimming Pool Light that enables complete mobile control of the pool’s colour.

IP Ratings

Of particular relevance to swimming pool lights is the Ingress Protection Rating, which is published by the International Electrotechnical Commission (IEC) and is universally used to classify and rate the degree of protection offered by an electrical enclosure against solid objects (including dust) and water.

The IP rating uses 2 figures, the first of which ranges from 0 to 6 and refers to the level of protection against ingress of solid objects. The ultimate ‘6’ rating is indicative of a completely dust-tight housing. For pool lighting the second number is more significant, which ranges from 0 to 8 and refers to protection against ingress of water. An IPX3 rating is considered to be the minimal requirement for outdoor lighting, whilst underwater lights usually require an IPX8 rating for submersion at an unrestricted depth.

Lighting around the pool

There are countless lighting possibilities beside or above a pool. One possible choice for overhead lighting is the Fireguard LED6 Dimmable Spotlight, which is ideal for creating mood in conjunction with a dimmer switch. A great source of general lighting, the Fireguard is IP65 rated and is fire-rated to preserve the integrity of the ceiling in the event of a fire.

Poolside lighting can increase ambience in spa or hotel pools, so products such as Deltech’s LED Flexi Strip allow you to get creative! This strip of LEDs is orderable in 5-metre lengths and can be installed around the perimeter of a pool for both ornamental and safety purposes. You can choose from white, blue, purple, or RGB colour-switching flexistrips.

Walkover lights also have an infinite amount of potential around the pool. They can be fitted into surrounding areas of decking, or even in the pool itself. Walkover lights are often submersible to various degrees. LED lends itself particularly well to this type of light, since it allows extremely small designs and is naturally vibration proof and shockproof.

Swimming Pool LightsLyco are able to offer suitable walkover lights in the form of the Garland LED Walkover Lights, which can be used around the edges of a swimming pool or to highlight water features. These are also a great idea for decking and shallow (1m max) submersion in a pool.

A final benefit in installing LED lights around the pool is their lack of attraction for insects and bugs. Because they produce vastly less heat than incandescent or halogen light sources, and don’t have the UV output that’s inherent in fluorescent lighting, LED lights are an entomological wasteland!

Looking for more news, inspiration and advice? Try our Lighting Advice section.


Andrew Evangelidis Head of Buying

Andrew is an experienced buying professional who takes an entrepreneurial approach to identify new lighting solutions and ensure Lyco have first-to-market ranges for our customers. Having previously worked for well known brands such as Wickes, Carphone Warehouse and Toys R Us, Andrew has now turned his hand to sourcing commercial lighting and ensure our customers receive top brand quality products at marketing leading prices. He manages a team of commercial and decorative buyers who travel the world finding new products that our customers don’t even know they need yet.

What are dichroic lamps?

The term ‘dichroic lamp’ almost always refers to low-voltage MR11 or MR16 halogen spotlights. The interior surface of these lights is designed as a multifaceted reflector (MR), with the purpose of gathering up the widespread light of the burning tungsten filament and projecting it forward through the front of the lamp.

Invariably the surface of this reflector is manufactured in one of two ways; it’ll either have an opaque aluminium coating or a dichroic coating. The purpose of an aluminium coating is uncomplicated: it projects as much light as possible forward without discriminating between visible light and invisible UV or IR radiation, either of which can potentially be harmful.

A dichroic coating is essentially a thin layer of non-metallic film, sometimes referred to as interference film, which reflects visible light from the filament forward whilst filtering infrared radiation and allowing it to pass through the back of the lamp. Since IR radiation is a significant source of heat, the net effect of this is to make the beam much cooler.

Dichroic compatibility

When buying or installing a dichroic lamp you first have to ensure that the light fitting or lamp-holder can dissipate the back-firing heat. Any recessed or enclosed luminaires that cannot accommodate such a lamp should be marked with the IEC 605598 ‘No Cool Beam’ symbol. If your light fitting is labelled in this way you’ll need an aluminium reflector lamp.


The beam of a dichroic lamp is significantly cooler than other halogen spotlights, which extends its usefulness drastically for displaying heat-sensitive objects such as paintings, photos, leather goods, food, and wine.

A second potential benefit of a dichroic coating is that it can be used to remove longer [redder] wavelengths of the visible spectrum to create a halogen spotlight with an unusually cool temperature. This has some appeal, because it’s ordinarily uncommon for a filament lamp to output anything other than a warm light, but there is a trade-off in colour accuracy and a lower CRI score. Most dichroic lamps remove only IR radiation and maintain their maximum CRI 100 rating for colour rendering.

Low-voltage MR11 or MR16 halogen dichroic lamps have other inherent advantages that complement their IR filtering properties admirably. With a relatively compact filament they are optically very controllable with minimal spill light, and deliver a focused, crisp beam. What’s more, they’re very affordable, and rarely more so than with the bargain-priced Lyco Halogen MR16, which is dimmable, highly colour-accurate, and might last you two or three years – all for mere pence! Looking for Low Voltage spotlights ?
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Other forms of dichroic lamp

Though dichroic lamps are mostly low-voltage, they can occasionally be found as mains spotlights. The common GU10 reflector is really an MR16 lamp with a ‘twist and lock’ 240V mains-connectable base. Cool-beam versions of the GU10 can be found with a dichroic coating, although they are known as ‘GZ10’ lamps. Great care needs to be taken in ensuring these lamps are installed into a fitting with sufficient heat dissipation.

The future of cool-beam halogen

The very need to handle unwanted heat in a lamp is, of course, indicative of poor energy-efficiency, and that places dichroic lamps in something of a precarious position. In Australia the common low-voltage 50W MR16 has already been subject to a phase-out, and there have been one or two reports in the UK of its imminent European demise. When this does come to fruition – and it seems only a matter of time – it is believed the more energy efficient IR-reflecting and Xenon-filled 12V halogen spotlights will remain available.

MR16 lamps have existed for over 30 years, and the threat of their extinction has caused some disquiet among lighting designers worldwide. With the more energy-efficient models seemingly safe for at least another three years or more, we might in that time expect LED alternatives to have been further improved and for their prices to have finally toppled. In the meantime, you can still reap the benefits of a crisp, bright, vivid, colourful, pretty cool halogen source of light!

For more advice, inspiration and news take a look at our Lighting Advice section.


Andrew Evangelidis Head of Buying

Andrew is an experienced buying professional who takes an entrepreneurial approach to identify new lighting solutions and ensure Lyco have first-to-market ranges for our customers. Having previously worked for well known brands such as Wickes, Carphone Warehouse and Toys R Us, Andrew has now turned his hand to sourcing commercial lighting and ensure our customers receive top brand quality products at marketing leading prices. He manages a team of commercial and decorative buyers who travel the world finding new products that our customers don’t even know they need yet.