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Aqua Illumination
Water Safe Lighting

This large ornamental fountain, located in Alpharetta, Georgia, is illuminated by six submersible LED fixtures. One of the first steps for the installation was trenching electrical conduit for the lights underground. Wires were connected to a lighting control panel in an equipment room that also contains the pumps. The wires were pulled first to a standard junction box, and then to separate underwater junction boxes. Once the fountain was turned on, the lights' positions and beam spreads were fine-tuned. The lighting controller adjusts the intensity of each fixture's red, green and blue diodes to create different colors.


The underwater lights for this medium-sized fishpond were installed while the pond was under construction. To allow easy access for maintenance, the crew used drop-in-place, or unfixed, LED fixtures and added a small bead of silicone between the retaining ring and the fixture's body, before submerging, to ensure a proper fitted gasket. Anthony Bogdanovich, owner of Imagine Lighting Co., and his team worked with the landscaper and the pond contractor to ensure the installation of the wiring was coordinated with their efforts.

The idea of having electricity underwater can seem almost contradictory in nature. Yet, today there is a plethora of products that can accommodate a diverse range of aquatic projects; from the smallest koi pond to the largest backyard pool, there is sure to be an underwater light that will shine.

There are two main types of underwater lights, fixed mount fixtures and movable uplights. Fixed mount fixtures are usually found in pools and usually require expert installation and handling - especially for a pool. Movable uplights, on the other hand, are ordinarily going to be weighted, small, waterproof light fixtures that can be easy to install. This article will address both of these waterproof landscape lighting varieties, including information on wiring, best practices, life expectancies, maintenance and safety regards.

Fixed Mount Fixtures
The major safety concern with any underwater lighting system is of course that electricity and water don't mix. But for large mounted fixtures there is an additional safety concern; heat. The sizeable lighting fixtures that are designed to be mounted underwater, work under the assumption that they will be constantly submerged in water to keep them cool., an online knowledge database for all things pool related, states, "water surrounds the entire fixture, keeping it cool. Do not operate the light for more than one second without it being fully submerged." To ensure that the lighting is properly cooled, the best practice is to have it installed a minimum of 18" below the water's surface, according to the installation manual for Hayward underwater lighting fixtures.

In regards to wiring underwater fixed-in-place light apparatuses, a dry conduit should be run from behind the fixture to a low-voltage transformer that is at least 10 feet away from open water and 12 inches above grade. Also, keep in mind that if your area is prone to flooding, the transformer may need to be installed higher. The conduit should not have any sharp turns because this could cause a splice in the wire and instead soft angles are advised. For the ends of the conduit, the Landscape Lighting Guidelines, supplied by the Association of Outdoor Lighting Professionals (AOLP), recommends that "All conduit that is terminated outside of the water source should be located at a minimum level of 8 inches above the water level at the water feature."


To illuminate this fountain at a house in Omaha, Nebraska, McKay Landscape Lighting used Focus underwater lights with pivoting bases for precise aiming. In the basin, they installed four, five-watt fixtures with 40-degree beam spreads. The two bowls above the basin have two fixtures each with four-watt lamps with 60-degree spreads.


The Atlantis 16 is part of Unique Lighting Systems' Odyssey series. The Atlantis 16 is made from machined brass and is designed to work in depths of up to 3 feet. This fixture uses a standard MR16 lamp and includes an integrated 180-degree rotational swivel bracket. The best practice for this specific fixture, according to the product's specification sheet, is to place it in shallow water and aim it at an element that is above the water's surface.

Installation of permanent mounted fixtures for a pool is difficult. relays that it takes major renovations to install pool lights into an existing pool. "We would suggest if you're remotely considering a pool light, it's best to have it installed during construction." Most local electrical codes require that a licensed electrician perform any pool electrical work. Although the installation may be challenging, maintenance on existing underwater mounted fixtures is relatively user-friendly. First of all, due to the permanent nature of these fixtures, life expectancies are usually on the high end, eliminating the need for frequent repairs. Low voltage LED light bulbs, the most common underwater bulbs in use today according to, have a life expectancy of around 50,000 hours; equating to 13.7 years of use at 10 hours a day. To replace a bulb, it typically requires loosening a single screw and pulling the fixture above the water's surface.

Always take the utmost caution when handling mounted fixtures for any underwater application. Information found on states that there have been 60 pool electrocution fatalities in the U.S. between the years of 1990 and 2003 due to faulty wiring in pool lights.

Moveable Uplights
On the opposite side of the underwater lighting spectrum, are movable uplights. These are almost always easier to install because they do not need to be mounted, simply placed and plugged in. This type of fixture will typically come with a weighted base to help prevent it from moving underwater. There are also lights that float on top of the water and require no installation aside from plugging them in. These lighting fixtures are not intended for areas that see human use because they could be knocked over and become dangerous.


This backyard grotto and waterfall feature, located in St. James, New York, was completed by Jeff Ingrassia, owner of FX Design Team, of Long Island, New York. Ingrassia states that the main challenge with this project was finding lights that could come in contact with water, but be installed above the water's surface. A total of four fixtures were used for the entire waterfall and grotto area: one on top, two underneath the waterfall and one far back in the cave. All four lights are connected to one junction by conduits that then runs to a separate transformer.



This is your standard, fixed mount LED fixture that is intended for landscape amenities that see human use, like a pool or spa. Installation for this type of underwater fixture usually requires a certified electrician to ensure proper safety guidelines are being followed. Maintenance for fixed mount fixtures, such as this, should only consist of bulb replacement. To do this, the single screw on the faceplate can be loosened to remove the fixture from the niche. Then simply raise the fixture above the water and replace the bulb. Fixed mount fixtures will most likely come with what seems like an excess amount of cord, however it is important to allow more than enough linage for the fixture to be removed from the niche and brought well above the water level.

The AOLP relates that "Non-permanent, unsecured fixtures and cable runs should be placed within the water feature to best hide these components. Rocks, stone, or other building materials can be used to hide the cabling and fixture(s), but they should not crush or damage this equipment."

Each connection, between the fixtures themselves, to either a timer or transformer, should be fastened with a turn-nut to ensure adequate waterproofing.

Many of these types of fixtures come with the capability of mounting if need be. Yet, remember, unfixed directional lights might require more routine maintenance and mounting them down means you will have to unmount them to change a bulb.

These recommendations and practices are for fixtures placed in freshwater, not saltwater. Regardless, anytime work is done with an underwater lighting appliance, do not forget to turn the power off to the system.

When perusing fixtures, it is common for all underwater lights to have a silicone "o ring" sealing the gasket, which prevents water seepage. This is a crucial piece of the fixture and should be included. If it is not, be skeptical.

The AOLP guidelines state that any transformer that will see connections to an underwater appliance must be specifically rated for submersible use. The transformer should have this clearly displayed. As mentioned afore, local guidelines regarding underwater light installation may be in place in your area, especially when dealing with pool lights. Each year the National Fire Protection Association publishes the National Electrical Code and posts it on their website, It is free to view for registered members (registration is free). According to their site, the code has become the benchmark for all 50 states regarding safe electrical design, installation and inspection.

Jeff Ingrassia offers this advice when dealing with underwater landscape lighting; "Check with your local municipalities for updated codes because some codes vary. Every township might have a slight differential and it's good to know the codes. It's also always good to work hand in hand with a certified electrician."

Whether your landscape calls for a mounted fixture or an unfixed directional fixture, stay safe and enjoy the idea that we live in a time where you can have beautiful lights placed safely underwater.

As seen in LC/DBM magazine, April 2018.

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December 11, 2019, 1:10 pm PDT

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