Red LED Flashlights.


Oct 24, 2009
I made this thread as a way to get cheap, quality red LED flashlights. This seemed to be the best place for it; if I'm wrong, please move it.

A lot of us here use red flashlights when we view the nocturnal denizens of our tanks. I would like to expound a bit on the virtues of a red LED flashlight compared to the traditional incandescent bulb with a red lens approach.

LED flashlights are superior to regular light bulb flashlights in that they convert much more energy from your batteries to light, as opposed to light and heat in an incandescent bulb. The second benefit, which is specifically what we'll be discussing here, is the narrow spectral output of a colored LED as opposed to an incandescent bulb.

If you have a traditional incandescent flashlight with a red lens, your bulb will emit broadband visible light from violet (~390 nm) to near infra-red (700+ nm). With a red lens, your light would still be emitting the same amount of broadband light, but only a narrow section of red and reddish orange light (from approximately 620-680nm) will be allowed to pass. That will result in the vast majority of your light being lost, killing the overall efficiency of the light.

You can get the same amount of red light from an LED flashlight that will have a MUCH longer battery life, as the red LED will emit only red light from roughly 635-645nm. I have two of these red flashlights, one is an Ultrafire with a factory red LED that turned out to be WAY to bright for tank viewing (but perfect for my military usage) and an AAA Mini-Maglight that I've modified to take a 5.5mm red LED. The Minimag has turned out to be the PERFECT solution for night-time tank viewing, as it gives off the right amount of light to see what's in the tank, but it's batteries last a very, very long time. Both lights cost me about $10 all said.

I can post a how-to tutorial on how to modify the Minimag if anyone's interested. If you own a drill, you can do it. It's as easy as falling down. :)

First I'll address the Ultrafire. I got this flashlight from Dealextreme. This is a good light and was cheap, it was $9.90 shipped to my door. This thing is tremendously bright, it will light up an entire room bright enough to read by. The main fault I have with it is that it's batteries cost twice what the flashlight did! If you get one, I would recommend getting the 18650 battery and charger from Dealextreme to go with it. It'll save you a lot of money.

In the pictures, keep in mind that because the lights are bright and monochrome, they wash out the digital camera fairly easy. They look red in person, not that yellowish orange color.

Ultrafire Pic-

Second, is my Minimag. Like I said, it has great battery life and is the perfect brightness for viewing your tank or nighttime bathroom trips (which is the primary reason I made it).

Here's some pics-

looks factory!

Comparison between the two-


Certified Ceph Head For Life
Staff member
Sep 4, 2006
Gainesville, GA
If I ever have a little fun money again, I want to look into the bright one (would actually prefer it could run using AC with a converter). Lighting up the entire room would be excellent on many occassions. Posting the miniMag conversion would be great since I suspect many of us have one or another of them.

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