Actinic & LED questions

Hello. I'm curious about the concept of "actinic" lighting. I read the stickied threads & searched all over the net trying to find a good definition of actinic, but don't seem to be able to find one that answers my questions. Is actinic just a word used to describe a certain spectrum of light, such as 420-460nm? Does an actinic bulb have a special coating or anything on it? I'm experimenting with some different lighting & am wondering if I use an LED that is 420nm if that is "actinic".

Also does anybody know what wavelength white light is. I've heard 5000K alluded to, due to the balance between red/blue, but don't know if that's the case. Does anybody have a formula to figure out the wavelength of light from its Kelvin rating?

Does anybody have any experience with DIY LED lighting that would like to give me some pointers?

Thanks!

 

for LED's, go with CREE royal blues for actinic, and Q5's for the whites. the higher the kelvin, the more blue spectrum becomes apparent.

~Will.

 

actinic: it actually produces all visible light but only in small amounts. it does produce an excessively large quantity of 420-480nm light, and thats why it looks blue. What they dont tell you is that it also goes below 420 nm and produces UV light. Corals phosfluorescense (glow) at their own specific wavelength. Most are between 300nm and 480nm. Actinics broadcast a lot of photons with wavelengths between those two values so they are very effective at exciting all types of corals.

Sunlight is between 5500K and 6500K, although we typically use 10000K in the hobby for white light because it just looks a little more crisp and still allows for fast coral growth.

And have you ever wired LED before because it is a very time consuming and tricky process. If you want to tackle it, that is the way to go for best PAR, color temperature, least energy consumption, no heat, and the nice shimmer effect. You may still need to add an actinic to get the colors to "pop"

 

Thanks Will, I'll check those out!

Dingo, thanks for the reply! I'm still not clear on the meaning of "actinic".
Do I need to find an "actinic" LED, or just find an LED that emits light in the 300-480nm range and that would be "actinic"? Perhaps I'm getting to stuck on the word rather than what it does. I've never wired LEDs before, but it sounds like a project I'd like to tackle. I'd like to get my power consumption & heat production down, and the configuration options with LEDs are exciting. ;D

 

lol, simply put: actinic = blue. if you do a 1 to 1 ratio of royal blues to Q5 whites you'll get a very nice 14k -15k look (not too blue, not too white, a very nice blend).

I hope you are a great solderer if your planning on tackling a DIY LED fixture.

~Will.

 

Thanks Will! I've done very little soldering, but I'd like to learn. I think I'm just going to take things slow and do some practice pieces until I have an idea on whether or not I can make this work.

 

Whats rough about the LED's is they are usually surface mount. If they came tailed anyone could do it, but those pads make it rough. You have to cut and strip your wire, then tin it, then tin the pad, then try to get the solder on the pad and the solder on the tinned wire to merge with a solid connection.

~Will.

 

To me actinic is only the 420nm (purple) range. 460 is blue. The bulbs in these two ranges vary drastically so I don't like grouping them together, but that's just me probably.

There is a series of good articles about light, part 4 is specifically about color temperature if you want to know more. The rest of the articles are really good too.

facts of light site:reefkeeping.com - Google Search=

 

Hmm, sounds difficult. I'll definitely need some practice.

@Screwtape: Thanks for the info. Great link, I'll give it a read!

 

i have worked with LEDS and made a simple nightlight with some blue leds for my tank when messin around (pic included)

as illwill said, the good LED's capable of providing solid PAR readings are surface mount. they require a higher precision of soldering than the basics... you need a really really good soldering station to do good quality work with them. if you have the time, patience, and money necessary to get the proper tools and such it would be a fun fulfilling project in my opinion.

edit: two pics of two revisions of my nightlight