This guide shows you how to determine if you have a bad light fixture and, if so, how to replace the whole fixture including the wiring to the fixture.

If you’re considering an inground pool, you are probably also considering installing an underwater pool light. As we work with hundreds of folks throughout Virginia, Maryland, and West Virginia each year we have the opportunity to answer tons of questions about pool lighting. In this article, we’re going to tackle some of the most popular inground pool lighting questions we receive on a daily basis.

Step 1

DETERMINE IF LIGHT FIXTURE IS BAD – If your light continually trips the GFI circuit, there’s a good chance that it has developed a short in the light fixture or wiring. At this point you will have to replace the whole light fixture and wiring. If you have two lights tied together than you will have to wire each light independently to test which light is tripping the GFI.

Step 2

TURN OFF POWER – Before working on your light fixture, be sure to turn OFF power to your lights at the circuit breaker.

Step 3

DISCONNECT LIGHT WIRES – Locate the power junction box for your lights. It will normally be next to the house close to the pool control box. Open up the junction box and disconnect the wires to your light  You may have several light cables coming into this box. Generally they are labeled on the PVC pipes. If not, you may have to disconnect each independently and turn the power back on and off to see which cable powers each light. Mark the pipes for the future.

Step 4

ATTACH CORD TO POWER CABLE – Once you have determine which cable you want to pull out, attach a cord or special fish tape to the wire. One way to do this is to bend back the white and black wires to form a loop. Leave the green ground wire out straight. Then attach the cord though the loop. The green ground wire will parallel the cord as shown.

Step 5

TAPE CONNECTION – Tape the wire connection on both side of the joint so that no wire ends are left exposed. A smooth connection will move around any bends in the pipe more easily.

Step 6

UNSCREW LIGHT FIXTURE – Remove the light fixture off the pool wall. It is generally secure by one screw at the top of the light fixture.

Step 7

PULL FIXTURE OUT OF NICHE – Pull the pool light fixture out of the niche. You should have enough excess cable to be able to lay the light fixture on the pool deck. Note how the excess cable is stored in the niche so you can replace it the same way when you install the new pool light fixture.

Step 8

PULL LIGHT CABLE OUT OF WALL – Pull the light cord out of the pool wall. There is a conduit between the pool and the J-Box at the house. When you pull out the light cable at the pool, you will be pulling the cable out of the conduit and pulling through the cord that you attached to the other end

Step 9

FEED CORD AT THE J-BOX END – As you are pulling cable on the light fixture end, have someone else feed the other end of the wire and the attached cord down into the pipe.

Step 10

PULL_OUT_CABLE-CORD_CONNECTION – After you have pulled out all the old cable, you will expose the connection of the cord and cable created at the junction box.

Step 11

TIE CORD TO NEW POWER LINE AT POOL – Once you have pulled the old light cable out of the conduit, take off the cord that was pulled though with the old cable and secure it to the free end of the new light cable. – like in Steps 4 & 5.

Step 12

PULL NEW CABLE AT J-BOX – pull the new light cable back into the conduit by pulling on the cord at the terminal box end of the conduit. Have someone feed the cable into the conduit at the back of the pool niche so that it doesn’t bind as you are pulling on the other end.

Step 13

LEAVE 4′ SERVICE LOOP AT POOL NICHE – Pull the cable through the conduit until there is 4′ of cable left at the pool side. This extra 4′ will allow you to place the light fixture on the pool deck when you have to service the light in the future.

Step 14

PLACE NEW FIXTURE INTO NICHE – Position the new light fixture in the niche by first recoiling and storing the excess cable as observed in Step 7. Then push the light fixture back into the niche.

Step 15

REPLACE PILOT SCREW – Replaced the single screw to secure the pool light fixture to the niche

Step 16

REMOVE EXCESS CORD AT J-BOX – Go back to the J-Box end of the cable and cut off the extra length of cable, leaving about 7 extra inches.

Step 17

ATTACH WIRES TO J-BOX -Use wire strippers to strip 6″ of the outer cable casing to expose interior wires. Strip about 1″ of wire coating off each wire and attach the cable wires to appropriate wires in J-box.

Step 18

REPLACE J-BOX COVER – Replace the J-Box cover and secure it with the screws removed in Step 3.

Step 19

TURN POWER ON – Turn the power to the lights back on at the breaker box.

Step 20

CHECK LIGHT – Check the new light at the pool to see that it is operating properly.

DETERMINE IF LIGHT FIXTURE IS BAD – If your light continually trips the GFI circuit, there’s a good chance that it has developed a short in the light fixture or wiring. At this point you will have to replace the whole light fixture and wiring. If you have two lights tied together than you will have to wire each light independently to test which light is tripping the GFI.

What should I know about pool lights?

Lighting your pool lets you swim at night with multicolored ambient light. LED pool lights allow you to change colors with a flip of a switch. In-pool lights must be installed during construction. Smaller LED lights cost $700–$900 installed, and fiber optics cost $1,300–$1,700. The only required maintenance is replacing the bulb.

Why should I light my pool?

First of all, lighting your pool will allow you to take full advantage of your pool both day and night. Many folks find night swimming a wonderful experience, but it’s simply not the same without ambiance of the reflective light that an underwater light provides.

Lighting your inground pool also allows peace of mind when watching little ones swim after dark as it adds better visibility throughout the entire pool.

Do pool lights have to be installed during construction, or can they be added later?

Some pool accessories can be added later, but pool lights don’t offer that flexibility…not without major renovation work anyway.

We would suggest if you’re remotely considering a pool light, it’s best to have it installed during construction.

How many lights do I need?

It depends on the type of light, but we currently use the smaller LED lights like the Globright or the Pal 2000 in our fiberglass pools and suggest that one light, at a minimum, will adequately illuminate a pool up to 30’ long. Pools longer than 30’ will require two lights. Please note that this is a bare minimum, most folks end up getting two lights in any pool, and some even have us install three on very large pools.

What are my lighting options and what are the pros and cons of each?

The predominant pool light on the market today is LED, but fiber optic lighting as well as incandescent lighting are also available. Let’s take a closer look at each.


LED stands for Light Emitting Diodes, illuminated by the movement of electrons within a semiconductor material.

LEDs have no filaments, so they emit no heat.

LEDs also change colors and have several light show settings.

LED bulbs have a very long life span…about 30,000 hours compared to the 5,000 hours of the incandescent and the 6,000 hours fiber optics. That’s the equivalent of SIX incandescent replacements and FIVE fiber optic replacements.

The smaller LED lights like the Pentair Globrite or PAL 2000 typically cost between $700 and $900 installed.

Fiber optic pool lights are usually around $1,300 to $1,700 installed.

Full size incandescent pool lights are typically in the range of $450 to $650.


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