460nm vs. 420 nm Actinics

zacharytrimble · 01/22/2007, 11:25 AM

What is the difference in these two besides the fact that 460 looks blue and 420 (03 "True") looks purple. Is one better than the other?

MCary · 01/22/2007, 11:30 AM

I don't believe actinics have much benefit to the tank. The difference would be one of personal taste. I find the purple ones make things glow more but seem a little dim (Speaking of a T-5 setup) where the ocean blue was brighter but didn't flouress much.

Mike

Aquabucket · 01/22/2007, 12:24 PM

You could run a nice tank on actinics alone. Many of the T5 actinics have pretty good PAR value. The difference between the 2 bulbs you mentioned will be looks (as was said) and the PAR ratings of the individual bulbs.

Actinics simulate light as it passes through water ~ much of the blue spectrum is what's left at deeper areas of the reef. More info on PAR values for individual bulbs can be found in the lighting and equipment forum.

RichConley · 01/22/2007, 12:29 PM

All correct. If you're using a mixed setup (T5 and MH), check out the spectral chart for your MH bulb, and if it spikes at 450, use 420nm actinics, and vice versa.

bureau13 · 02/12/2007, 04:18 PM

Anyone actually measure the spectral output of AquaMedic's Ocean Blue T5HO bulbs? I thought I knew what was going on...these are visually very blue, so I figured they must peak at 460. This made perfect sense, since they're paired with AB10000K bulbs, which have a spike at 420 according to Sanjay's charts. Since I'm thinking of going Phoenix, which have a blue spike at 460 or so, I was thinking of replacing the Ocean Blues with UVL Super Actinics, a 420 bulb. Then I found AM's description of their Ocean Blues...they claim a spectral peak of 420! They also showed a plot, which appeared to back this up save for a VERY narrow spike at 460. I just don't get how a 420 bulb is more purple, if the Ocean Blues I have are 420.

jds

01/22/2007, 11:25 AM	#1
zacharytrimble Registered Member Join Date: Dec 2005 Location: Ohio Posts: 456	460nm vs. 420 nm Actinics What is the difference in these two besides the fact that 460 looks blue and 420 (03 "True") looks purple. Is one better than the other?

01/22/2007, 12:24 PM	#3
Aquabucket Premium Member Join Date: Jun 2003 Location: Green Bay, Wi. Posts: 4,455	You could run a nice tank on actinics alone. Many of the T5 actinics have pretty good PAR value. The difference between the 2 bulbs you mentioned will be looks (as was said) and the PAR ratings of the individual bulbs. Actinics simulate light as it passes through water ~ much of the blue spectrum is what's left at deeper areas of the reef. More info on PAR values for individual bulbs can be found in the lighting and equipment forum. __________________ "Just a drop in the bucket" Last edited by Aquabucket; 01/22/2007 at 12:36 PM.

01/22/2007, 12:29 PM	#4
RichConley Registered Member Join Date: Sep 2004 Location: Bostonian in Chicago going to DC Posts: 9,908	All correct. If you're using a mixed setup (T5 and MH), check out the spectral chart for your MH bulb, and if it spikes at 450, use 420nm actinics, and vice versa. __________________ NO TANKS!!!

01/22/2007, 11:30 AM	#2
MCary Premium Member Join Date: Dec 2002 Location: Hardin, Montana Posts: 3,142	I don't believe actinics have much benefit to the tank. The difference would be one of personal taste. I find the purple ones make things glow more but seem a little dim (Speaking of a T-5 setup) where the ocean blue was brighter but didn't flouress much. Mike

02/12/2007, 04:18 PM	#5
bureau13 Registered Member Join Date: Apr 2005 Location: South Florida Posts: 1,936	Anyone actually measure the spectral output of AquaMedic's Ocean Blue T5HO bulbs? I thought I knew what was going on...these are visually very blue, so I figured they must peak at 460. This made perfect sense, since they're paired with AB10000K bulbs, which have a spike at 420 according to Sanjay's charts. Since I'm thinking of going Phoenix, which have a blue spike at 460 or so, I was thinking of replacing the Ocean Blues with UVL Super Actinics, a 420 bulb. Then I found AM's description of their Ocean Blues...they claim a spectral peak of 420! They also showed a plot, which appeared to back this up save for a VERY narrow spike at 460. I just don't get how a 420 bulb is more purple, if the Ocean Blues I have are 420. jds