Choosing a 12 V LED pool light

A pool light is a small purchase that asks for a big commitment. It goes into a wall under water, at the end of a cord pulled through a buried pipe. Getting the wrong one means draining, pulling and starting again.

An installer settles the choice in a fixed order: the niche, the voltage, the body, the control, the cord. The same order works for a buyer.

Older pools were built with 120 V lamps in sealed housings. They work, and they put mains voltage a lens away from the swimmers. A fault in an old fixture is the kind of failure that safety agencies warn about.

An LED needs far less power than the lamp it replaces, and it runs happily on 12 V. So the mains voltage can stop at a transformer on the wall, well back from the water, and only 12 V travels down the cord to the light. Every pool light we make works this way.

Low voltage at the light does not make the job a do-it-yourself one. The control box still joins to house wiring near a pool, and that connection has rules of its own.

The niche is the cup set into the pool wall that holds the light. Sizes are not universal. Most fall into two groups: small niches about 6 inches across, common in spas and newer pools, and large niches of 10 to 11 inches in older in-ground pools.

No niche at all is also an answer. Vinyl and fibreglass pools often have a plain wall fitting. Our 6 inch lights thread onto a 1/2 inch fitting or screw flat to the wall, so they suit those pools as well.

Here is the full set. Watts and lumens come from the product details, prices are current, and the ratings are what buyers have given each model so far.

Read the ratings before the other figures. They differ a good deal from model to model, and the reasons follow below.

Our 6 inch lights give 6,000 lumens from 60 W. The 10 and 11 inch lights give 12,000 lumens from 120 W. That is 100 lumens for each watt on either size.

A dark plaster finish soaks up light and a white one throws it back. A buyer who replaced an older brand-name fixture wrote that the one old light could not light the whole pool, and the new one does. Another buyer, with a 1.5 inch pipe fitting and a 60 W light, was satisfied with one.

No chart can size a pool it has not seen. Count the niches you have. A pool built with two niches was designed for two lights, and one bright light in one corner leaves the far end dim. Colour changes the picture as well: a deep red or blue looks dimmer than white from the same lamp.

The body is what sits in chlorinated or salted water for years. We make three kinds, and buyers have told us plainly how each one fares.

We will single out the P10 Small-Niche Pool Light. It is our lowest-priced pool light and our lowest-rated. Buyers describe corrosion within weeks and paint peeling within 6 months in treated water. If your pool is chlorinated, a polycarbonate light is the safer pick from our range.

A 12 V colour light needs two things on dry land: a transformer to make the 12 V, and a controller to tell the LEDs which colour to show. A control box puts both in one case.

The P9 Pool Light with Controller Kit ships with the C3 box, which gives 200 W. That is enough for three 60 W lights or one 120 W light. The C1 400 W LED Control Box is the larger case at 400 W, for three 120 W lights or six 60 W ones.

Add up the watts of every light on one box and stay under its output. Four 120 W lights need 480 W, which is more than the C1 can give. Split them across two boxes.

A bare light such as the P9-2 Pool Light, 12 V has no box in its carton. It needs a 12 V supply and a controller such as the WiFi and RF Remote Controller Kit. Buyers who expected a remote in the box of the bare light were caught out.

Each kit comes with a radio remote. It works through walls at up to 100 ft and needs no network. The app adds timers, music modes and voice assistants, over 2.4 GHz WiFi or Bluetooth.

The remote is the dependable half. Across our pool lights, the most common complaint is an app that would not pair or would not stay connected. One buyer solved it by giving the controller a fixed address on the home router. Others gave up and used the remote alone.

On the P11, the on and off timer lives in the app and not on the remote. If you want the light on a schedule without the app, put the control box on a timer switch.

Our lights come with 50 ft of cord. Measure the run before you order: from the niche, down the conduit, up to the box, with a few feet spare at the pool end so the light can be lifted onto the deck for service.

Pulling cord through an old conduit is the worst part of the job. The P11 Pool Light with 2-in-1 Controller avoids doing it twice. Its cord ends in a 4-pin plug at the back of the light, so a failed light unplugs at the wall and the cord stays put. A spare 4-Way Pool Light Wire, 50 ft is sold separately.

That design is sound, and the P11 has still earned poor marks from the few buyers who have rated it. Two had a light stop within 3 months. We tell you so that the plug does not sell you the light by itself.

This is what the electrician will do, so you know what you are paying for and what to have ready.

Read the manual's line on running the light out of water. A pool light is built to work submerged, and its manual limits how long it may run dry.

A safe installation stays safe only if someone looks at it. Ground-fault devices have a test button for that purpose.

Learn the warning signs as well. A light that flickers, or comes on when it is switched off, is telling you something. Several of our own buyers reported lights that switched on by themselves. Whatever the cause, the response is the same.

Our pool lights mix red, green and blue LEDs. The controller sets how much of each is lit, which is how one lamp shows 16 million colours. In practice people settle on 4 or 5 of them.

White from an RGB lamp is all three colours at once. If you want a tunable white, the C1-1 controller also drives RGBW and RGB + CCT lights, and it has 5 output modes for that purpose.

The controller remembers its last state. Cut the power at the wall switch, restore it, and the light returns in the colour it had. That lets an ordinary wall switch act as the daily on and off.

Lights on the same control box change colour together. That is what most owners want: one pool, one colour. A second box gives a second zone, for a spa that should glow red while the pool stays blue.

The controllers also pass the remote's signal along. One controller repeats it to the next within 100 ft, so a single remote can reach a box that sits out of its own range.

You can save an hour of paid time by having the answers ready. None of this involves touching a wire.

• The inside width of each niche, in inches.
• The length of the cord run from each niche to the wall where the box will hang.
• The number of lights and the watts of each.
• Whether the pool water is chlorinated or salted.
• A photo of the old light's label, if it can still be read.
• The location of the breaker for the pool lights.

Ask the electrician two things in return: whether the old conduit is clear enough to take a new cord, and where the control box may be mounted under your local code. Both answers can change which light you order.

• Ordering a bare light and expecting a remote in the box.
• Measuring the old face ring instead of the niche.
• Putting 4 large lights on one 400 W box.
• Draining the pool and booking the installer before checking that the app would pair.

The last one cost a buyer of our P12 a pool technician's visit. Test the controller and the remote on a table before anything goes in the wall.

The praise is for brightness, colour and price against the big pool brands. The complaints are about the app, about lights that failed inside a year, and about corrosion on the metal P10.