PC actinic or blue 7100?

[Chris A.]

Wich of them would you get and why?Just bought a pc fixture and want to order the bulbs soon.Thanks

 

[MartyM]

I'd go with the actinic. A while ago bought a PC fixture that used two 7100 K bulbs. When I replaced them with 'true' actinics there was a noticeable difference in appearance. The corals definitely 'glowed' more under the actinics.
FWIW I'm a fan of hellolights.com PC bulbs. I've used serveral brands and theirs are the brightest by far.

 

[clamm]

Although I dont use pc now, I prefer actinic...it will give a deeper/richer purple/blue then the 7100

 

[dz6t]

Have you heard of something like a 50/50 PC bulb with the Actinic tube dead?

 

[me2003]

I prefered the blue 7100. I had 2 with 2 Ushio 10k 175 metal halides
Why
I was able to grow acros/corals well under this combination.
Steve Tyree gave a presentation about light spectrum from
MH bulbs and the desired spectrum for growing corals. His theory
was combining different MH bulbs would give you a better light
spectrum for growing corals. I believe the 7100 creates a peak
wavelength that worked well with corals. The presentation materials
may be available from BRS. I had a CD once of the info. I am not
sure how much a correlation there is to fluoresence and coral growth.
The 7100 look like they were brighter. That may be just the wavelength
of the light.

 

[me2003]

The 50/50 bulbs do not produce as much light as a 10k pc.
As a single light over a aquarium a 10k works the best.
If you have two pc a combination of 1 10k and 1 blue or actinic
looked brighter than 2 50/50. I always thought the 50/50 bulb
existed more for marketing reasons.