Santa Monica Filtration

Santa Monica Filtration GEM5 LED Lights for Algae Scrubbers and Refugium


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The GEM5 is the very first light ever designed just for algae scrubbers and seaweed cultivators. Because of the very wet and splashy environments that waterfall scrubber lights must operate in, and the underwater environments that some upflow scrubbers must operate in, these GEM5 lights are made with a high tech material which not only seals out water but also removes heat from the LED so that it remains at the proper operating temperature in any environment, submerged or not.

The GEM5 can also be used for underwater algal growth in hydroponics, illuminating the roots of the plants to grow algae on them; this adds oxygen to the water and to the roots themselves. And if you have or are building a chaeto reactor, put some GEM5 lights on the outside of the reactor (shining in), or on the inside of the reactor (in the water), especially at the bottom (shining up).

Each GEM5 light uses 5 real watts (volts X amps) for the power; it does not use "equivalent" watts like CFL lights do, and it does not "say" 5 watts but only use 3 watts like almost all LED grow-lights do. Because it uses real watts, each GEM5 light puts out the same algal-growth illumination that a "larger" 10 watt LED or 20 watt CFL bulb does. The GEM5 is pure deep red 660nm (nanometer), which is the primary growth spectrum for macroalgae (seaweed), and is also easier on the eyes when you have to look at it.

The power supply for the GEM5 is a fully isolated, low-voltage, LED power supply that is CE, UL, Canadian UL, and FCC approved. One power supply can power 1, 2, 3 or 4 of these GEM5 lights, using the 4-plug connector included. Any of the 4 plugs that are not used are to be capped off with the included caps. With 4 lights, you are getting a full 20 watts of illumination output, which is the "equivalent" of 40 watts of regular (especially Chinese) grow lights, or 80 watts of CFL bulbs.

The real beauty of a GEM5 light, however, is it`s all-environment capability. It`s patent-pending case is a solid (not hollow) high-tech material which not only completely seals the LEDs when under water, but also removes heat from the LEDs when above the water. This is very unique because normal resin or silicone would trap so much heat inside that the LEDs would burn up. The high-tech material used in the GEM5 means the light requires no cooling fans or heat sinks when operated in the air, and requires no waterproofing when operated under water. Matter of fact, if you have 4 of the GEM5 lights (with one power supply) you can put 2 of the lights on one side of your growth in the air, and the other 2 lights on the other side of your growth in the water. And this includes setting the lights on the bottom of your sump so they shine up from below! Don`t try that with your Chinese grow lights.

The GEM5 was designed because of the severe lack of lights for algae scrubbers and reactors, and the nonexistence of lights for underwater hydroponics. If you were building a waterfall or horizontal river style scrubber, up until now you either had to build your own LED circuit board and then put it behind a clear protective sheet, or you had to get a big bulky plant-grow light and try to find room to mount it and worry about line voltage being near the water. And if you were building an upflow style scrubber, your only choice was to put a light on the outside of a sump, shining through the sump wall; there was no easy way to get light on the other (wet) side. And even if you were just growing chaeto, all you could do was put a light over the top of the sump; it was very hard to put a light on the sides of the sump, and impossible to put one below, so those areas stayed dark. And dark does not grow or filter. And lastly, once you finally got your configuration set up, you still had almost no way of adding extra lights later.


  • Dimensions: Each GEM5 light is 7.5" long x 1" wide x 1/4" thick (190 mm long x 25 mm wide x 7 mm thick)
  • Cord length: The power cord is 10’ (3 m) from the plug to the light, which allows the power supply box to set far away from the light.
  • Underwater Rated: IP65, IP66, IP66K, IP67, IP68, IP69K (high pressure steam proof)
1 - 5 Gallons 5 - 10 Gallons 10 - 40 Gallons 55 - 120 Gallons 180 - 300 Gallons 450+ Gallons
RAIN2 x2 x3 x5
DROP.2 x2
Saltwater only
HOG.5 x2
x2 x4
HOG1.3 x2 x4
HOG2 x2 x3 x5
Saltwater only
x2 x3 x4
Saltwater only
x2 x3 x5
Saltwater only
x2 x4
Saltwater only

Product Manuals & Documentation

Santa Monica Filtration GEM5 LED Lights for Algae Scrubbers and Refugium

Owner's Manual available for download in Adobe PDF file format
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