View Full Version : Actinics 420 vs 460 nm - which to choose

08/17/2009, 09:27 AM
Hi gang,

I want to order some actinic T5 replacement bulbs for a 36" Nova extreme pro fixture and am having some trouble trying to decide what wavelength to target. I know down in this 400nm range is where a lot of photosynthesis happens, does anyone know what range coralline algae likes best? Current makes the actinics in either 420nm or 460nm, I just didn't know which to buy.

thanks again

small alien
08/17/2009, 01:47 PM
One thing I'd say is Current bulbs kinda suck in terms of output and life. You can get ATI or Giesman for almost the same price. Try a different brand. Someone else will have nm info for you. Good luck.

08/17/2009, 01:50 PM
Op for the 420 as that is a peak chlorophyll absorption wavelength. It will also produce a more pronounced fluorescence as it it lower in the UV spectrum,

08/17/2009, 03:40 PM
I like the looks of 420 over 460, but if you can mix the two of them, you will get a wider range of colors out of your tank

08/17/2009, 03:54 PM
Thanks for the replies everyone. I like the "mixed" idea, right now I run three actinic bulbs per fixture so I'll get two 420nm (per waterkeeper) and one 460 for the replacements

thanks a lot!

08/17/2009, 04:51 PM
The dual actinics are nice, but they have a sky blue tint to them that (for me) don't give quite the same high contrast punch that pure actinic provides.

scuba guy ron
08/17/2009, 05:07 PM
I run a regular 420 and 460 along(not t-5) w/ 150w mh over my 37g column tank. I've never seen my corals look as good as they do now. color totally pops!

08/17/2009, 05:37 PM
420nm for corals, 460 for tank color. really good energy in both areas are needed for an overall good look. 420nm is hardly noticeable to the eye when run along side white light while 460nm adds a noticeable blue tint. corals however utilize 420nm to grow color pigment.