Recommend me a T5 bulb 'layout'

[cmantis]

I have a 6 bulb 18" T5 light that needs new bulbs. Here are the available options:

AquaticLife:

Marine 700+ 10000K: Bright white light caters to the biological requirements of corals and aesthetic appeal of the aquarium.

420/460nm Dual Actinic: Mix of Actinic and Royal Phosphors produces a light spectrum that benefits most corals and enhances fish colors.

Purple: Phosphor mix produces a light spectrum that accents red pigments in corals.

CurrentUSA:

12,000K White

460nm Actinic Blue

 

[cmantis]

Where all the t5 reefers hiding?

 

[jackson6745]

Not sure what they make in 18", but for 24" and larger I like 4 blue+, 1 purple, 1 coral+

 

[cmantis]

I posted the available bulb options in first post.

 

[BKLYNREEF123]

with those options I would go 2 of each if its too white maybe order one more 420/460 to swap out in place of the 2nd white.

 

[fredro]

Not sure what they make in 18", but for 24" and larger I like 4 blue+, 1 purple, 1 coral+

No whites/6500ks?

 

[BKLYNREEF123]

Coral + is pretty white

 

[cmantis]

with those options I would go 2 of each if its too white maybe order one more 420/460 to swap out in place of the 2nd white.

I am really good with LED spectrum but without seeing the spectrum graph of each bulb am unsure what would be best for growth which is my objective.

What does the Purple do is it just to flouresce the corals?

Would 2 white, 3 blue and 1 purple be better?

 

[jackson6745]

The purple is great to tone down the blues while bringing a little something to the spectrum. Hard to explain really. It doesn't fluoresce the corals. I would go 1 purple, 1 white, 4 blue.

The overall spectrum is whiter than a 20k look. It really depends which white you go with. A 65k will bring you to a 14k look, where a higher k white will bring you somewhere between 14k-20k overall. Definitely don't use 2 white unless you want a 10k look.

In this link I ran 4 blue, 1 purple, and 1 65k for spectrum reference. Please excuse the starved zeo look lol
http://www.nano-reef.com/featured/_/2010/podpimp-r40