420nm vs 460nm actinic

[dwculp]

I need to order new bulbs for my 40 gallon reef. I have always bought 460nm 96W square pin bulbs when I needed actinic bulbs.

The place I order from is out, but they do have 420nm actinic and a 50/50 (420nm/460nm) bulb.

What is the difference (besides being 40nm difference in wavelength)?

[michaeldaly]

I think the 420nm will cause corals to floures more but I migh be wrong.

[sir_dudeguy]

420's are TRUE actinics (also more commonly known as 03 actinics). They are more purple and cause the corals to fluoresce a lot more. The 460's are way brighter and bluer but dont get the corals to show that neon green quite as much. Right now on my 40 i just got some new bulbs for my 4x96 pc fixtuer. I've got the regular 10K's for 2 of the bulbs, then the other bulbs i have are one 03 actinic (or 420nm) and one of the "blue" bulbs (460nm)

I have to say that i enjoy this combo much better than when i used to just have 2 03 actinics and 2 10K daylights. The blue one adds so much more color while the o3 is hardly seen, but it makes the corals fluoresce a bunch.

IMO, go with the one that is a 50/50 with half being 420nm and the other half being 460. You'll like the color combo. I'll get a pic of my tank w/just actinics on in just a minute...the 460 makes it quite a bit brighter...

[Randall_James]

50/50 bulbs are typically 10k/actinic I would verify that they are in fact 460/420. Sounds odd....

The difference is pretty slight all the same IME

[dwculp]

<a href=showthread.php?s=&postid=8560728#post8560728 target=_blank>Originally posted</a> by Randall_James
50/50 bulbs are typically 10k/actinic I would verify that they are in fact 460/420. Sounds odd....

The difference is pretty slight all the same IME

They are 420/460. Ive seen them for years and never ordered them as what I have been doing works well. Now the place I order from is out of straight 460nm bulbs so I guess it is time to try them out.

Here is the desctription from the site:

Compact Fluorescent Square Pin Bulbs SunPaq Dual Actinic
420/460nm 96W

[Randall_James]

I do have pics of the 2 wavelengths
The 460 is more purple (blacklight) to the 420 blue color, I have not run square pin so probably why I have not seen them

[dwculp]

<a href=showthread.php?s=&postid=8560801#post8560801 target=_blank>Originally posted</a> by Randall_James
I do have pics of the 2 wavelengths
The 460 is more purple (blacklight) to the 420 blue color, I have not run square pin so probably why I have not seen them

I think Current is the only company that makes a dual actinic bulb.

[sir_dudeguy]

50/50 bulbs are typically 10k/actinic I would verify that they are in fact 460/420. Sounds odd....

they've got the 50/50 with the blues too. Check out hellolights.com i think they've got em.

But there is a very big difference in between the blues. Actinic is way more purple and blues are...well..blue lol.

here's a pic of my 4 bulbs. The middle 2 are the daylights and the one on top is the 03 actinic...dont know why my camera did this but it made it look really bright and way more colorful than they really are. (03's are the same thing as 420nm)

Then the one on the bottom is the 460nm which again turned out weird in this pic...but you can still definately see a difference, and in person, there is way more of a difference (specially in brightness...the 460 is way brighter)
http://i75.photobucket.com/albums/i295/sir_dudeguy/Tank%20Pics/IMG_1780.jpg

here's my tank under just the blue lights (03 actinic and the 460nm "blue")
http://i75.photobucket.com/albums/i295/sir_dudeguy/Tank%20Pics/IMG_1755.jpg

and here is a pic from when i had two 03 actinics on my 55. Lots different and nowhere near as bright as it is now with the 460nm. As you can tell, it wasnt even really bright enough for my camera to focus right...
http://i75.photobucket.com/albums/i295/sir_dudeguy/Tank%20Pics/P1010318.jpg

[dwculp]

Thanks for the pictures, it really illustrates the difference. Normally I get the following:

1X 96W 10K daylight
1 X 96W 10K/460nm
1 X 96 W 460nm

I think this time I will replace the 96W 460nm with a 96W 420/460 and see how it works out!

[sir_dudeguy]

so you have a 3 bulb fixture? weird...

But also, i'd get a full 10K rather than a 10K mixed with anything (well anything blue anyways). When you get 50/50's as your daylights, you dont get as good of PAR rating.

So if you've got a 3 bulb fixture, i'd get 2 full 10K's and the one 420/460 one. But i've never seen a 3 bulb pc fixture...

Oh, and sorry i couldnt get a pic of the full tank when i had both 03 actinics...i honestly wasnt very impressed w/how the tank looked with them at the time so i tended to not do much other than take care of it lol...no pics really.

[dwculp]

Actually, it is two fixtures, a dual 96W fixture and a single 96W fixture. Both of them are Coralife Aqualights.

You dont think 2/3 daylight and 1.3 blue would look too odd? I like the blue in the mix as it cuts down some of the harshness of the 10K daylights, gives it a softer hue.

[sir_dudeguy]

Well for a while i was only running 3 bulbs on my 4x96 pc fixture. 2 10K's, and one 03 actinic. And honestly, it wasnt really that bad. And thats with a cheap ebay actinic bulb, and a really purple one at that. I too like the blue look, and with just one 03 it wasnt too bad...

But i'd assume that if your "actinic" bulb is at least half 460...it'd be much better than an 03

[dwculp]

Ok, I feel a bit stupid now.

A week or two after putting the bulbs in place I notice that the 420nm side of the 420/460 bulb is not working. I write Drs. Foster and Smith and they said to send it back and they would replace it. I ordered a new bulb and figured I would send the old one back in that package.

The new bulb arrived and I plugged it in and guess what.

One side didnt work.

I though "Oh no, the ballast is out." So, I yanked the bulb and tried it in other fixtures with the same result.

I looked down the end of the bulb and it appeared to be lit. So I killed the lights and sure enough, there it was glowing purple. You just couldnt see it with all the lights on. It was being washed out by the brighter 460nm side.

Now I have an extra bulb!

[sir_dudeguy]

lol ya you cant really see real actinic (03) burning when the daylights are on (and even when it sits next to my blue light you cant really....just gets drowned out as far as what you can see of it).

But someone earlier said that 460 is true actinic and 420's are blue...but its the other way around. Just throwin that out there ;)

[Randall_James]

<a href=showthread.php?s=&postid=8832487#post8832487 target=_blank>Originally posted</a> by sir_dudeguy
lol ya you cant really see real actinic (03) burning when the daylights are on (and even when it sits next to my blue light you cant really....just gets drowned out as far as what you can see of it).

But someone earlier said that 460 is true actinic and 420's are blue...but its the other way around. Just throwin that out there ;) I can see mine just fine next to 10K's

Anyone of these should be clearly visible that they are "On" next to a 10K bulb.

Here is a link with plenty to read on :)

http://wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm

[syrinx]

One side will look almost off in comparison to the other. It prob is working.

[yeldarbj]

I've got the Coralife 2X96w PCs. It came with the full 10K and full Actinic 03 (420 nm). I finally switched the Actinic 03 with the Current dual actinic 420/460. The colors on my zoanthids are much better but still get washed out when the 10K is on. The 460nm tube is much brighter than a 420nm. Later today, I'm supposed to receive the current dual 10K/460nm bulb (it came broken in the first shipment). I'll let you know later today how it looks.

I'll have 1 420 tube, 2 460 tubes, and 1 10K tube.

[dwculp]

I have to admit, with the 420nm on my corals look much better!

You will like the 10K/460nm bulb.

[dwculp]

<a href=showthread.php?s=&postid=8833579#post8833579 target=_blank>Originally posted</a> by syrinx
One side will look almost off in comparison to the other. It prob is working.

It is definitely working, you can see the 420nm side glowing purple if the room lights are killed.

[mnestroy]

<a href=showthread.php?s=&postid=8831269#post8831269 target=_blank>Originally posted</a> by dwculp
Ok, I feel a bit stupid now.

A week or two after putting the bulbs in place I notice that the 420nm side of the 420/460 bulb is not working. I write Drs. Foster and Smith and they said to send it back and they would replace it. I ordered a new bulb and figured I would send the old one back in that package.

The new bulb arrived and I plugged it in and guess what.

One side didnt work.

I though "Oh no, the ballast is out." So, I yanked the bulb and tried it in other fixtures with the same result.

I looked down the end of the bulb and it appeared to be lit. So I killed the lights and sure enough, there it was glowing purple. You just couldnt see it with all the lights on. It was being washed out by the brighter 460nm side.

Now I have an extra bulb!

Didn't you notice the little note taped to the bulb that said "Yes this bulb is working!" ? :)

[dwculp]

<a href=showthread.php?s=&postid=8834154#post8834154 target=_blank>Originally posted</a> by mnestroy
Didn't you notice the little note taped to the bulb that said "Yes this bulb is working!" ? :)

If there was a note attached to it, I didnt see it.

Love your avatar. I want to name my first kid Stewie!