8 bulb t5 config and purple plus vs. fiji purple answers

[adamt]

I ordered bulbs from reef geeks today I am going with the following set up

front
blue+
blue+
aquablue special
blue+
fiji purple
blue+
aquablue special
blue+

I originally was going to go with the purple plus over the fiji purple but after looking all over the place I was finally able to prove what I already knew: the fiji purple is a better bulb. The purple blue range of these bulbs is almost identical... where they differ is in the red range. The purple plus has a peek in the orange/yellow range, while the fiji purple peeks right in the middle of the red range. The red is more usable light and it keeps the tank from "yellowing out". Heres a link that compares spectoral output

http://reefgizmo.com/2011/01/kz-fiji-purple-vs-ati-purple-plus/

bottom line: if you can afford the extra $8 go with the fiji purple

 

[rsuplido]

Thanks for linking to my blog.

The Fiji Purple is indeed a great bulb but there is this article about red light (scroll to the bottom) that can stunt the growth of corals: http://www.advancedaquarist.com/2008/12/aafeature1

 

[adamt]

Interesting study, although i do have some issues with the way it was carried out. In one respect it supported something that I think is obvious to most experienced reef keepers/divers: blue light penetrates deeper and as such photosynthetic species in these zones have adapted to use this light. (thats why 5 of the bulbs of my 8 bulbs are blue and even the other three show strong spikes in the 460 nm range).

In terrestrial plants red light triggers a flowering response, along with that comes a loss of foliage as the plants focus their energy on budding. It does not suprise me at all that a poccillipora would not flourish under pure red led diodes.

I wish the study would have looked at coral growth under a baseline of 20000k or 22000k and compared the differences when supplemental red light was added to one of the study groups.

I found nothing in that study to suggest that red light when part of a wide spectrum including blue in the 420-460nm range does anyting to stunt coral growth. There was also no mention of the light that frags or mother colony were originally grown under. It seems obvious to me that coral that was grown under 20,000k light that was then fragged and placed under purely red light would suffer from algae loss and stunted growth. I believe that the reason that red light caused more algae loss than shading is because photosynthetic organisms are designed to react when red light hits a cetain % of the overall spectrum the plant recieves.

Even though red light is quickly filtered out by ocean water, there are a number of sps species hobbyists keep that grow in shallow enough water to have adapted to utilize it.

When it comes to puple plus vs fiji purple I want the one with a higher red peak for one reason: i have red corals. The yellow and orange from the purple plus do little for me visually, and since I am only using one purple bulb I went for the one with the most red. The aqua blue specials (as blue-white as they are) still provide all the yellow and orange I need.

Thank you for sharing that study but I hope anyone reading it is not scared off of utilizing bulbs with red peaks because when incorporated as part of a balanced spectrum used by hobbyists I do not believe this study showed it would pose any threat to coral growth.

In addition to the ati and kz bulbs i ordered I am also getting a uvb 2.0 bulb (commonly used for reptiles), I am going to attempt to study if the additional low level of uvb (250-350nm) radiation does anything to my sps. I am only going to use 1 bulb and I am going to replace one of the aquablue specials with it. Despite being a uvb bulb it has a full spec appearence so visually I dont think it will affect the look of the tank. Ill let you guys know what happens!