purple bulbs - effects on corals, algae?

[jeremy K]

I am wondering about the purple T5 bulbs (ie. ATI purple plus, KZ Fiji Purple). I know that these are heavy in blue and red spectrum, thus forming the purple color (rather than being a true violet bulb like an actinic).

Due to the high red content, are these bulbs likely to grow algae significantly? Are they likely to brown out corals due to zoox reproduction?

I ask because I really like the color of these bulbs, especially combined with true actinics. If I could, I would run just purple and actinic bulbs on my tank. But I wonder what effect this would have on my corals and algae levels...

 

[nycreef]

Funny you mention this because I was actually looking for a T5 Black light bulb to bring out the fluorescence of my corals and fish. Im not sure if this is the same bulb as the one your mentioning cause i did sssee the purple bulb you mentioned as well. Almost bought one at home depot but decided to wait untill i researched it a bit more. I dont think I would run it with my lights but only when my actinics are on alone. Im not positive but I would think it would inhibit algae because of the spectrum.

 

[texasrainman]

Last time I tried a black light, it lit up all the particles in the water.

 

[jeremy K]

No, I'm not talking about black lights. The purple bulbs I mention are strong in red and blue, combining to make purple. Black lights are actual violet and UV spectrum bulbs - the closest to those that I would use in a reef setting are true actinic bulbs. But I am specifically talking about the ATI purple plus and KZ fiji purple bulbs.

 

[power boat jim]

I use both of those bulbs to pop the red color out, they dont cause an abundance of algea growth. That is usually caused by a higher nutrient level in the water then soley by the lighing system.

 

[Bikermike]

I love putting them underneath the tank under the rocks before you set everything up so it shines through the rock, looks amazing, but it goes without saying you can't use t5s for that.

 

[bigchris7226]

I run 2 Purple+ & 4 Blue+ on a 40br sps and have no algae issues & great color. Growth is averaging around 1" a month-no negitive effects whatsoever.

 

[SushiGirl]

We run 1 purple, 1 white (I think), 1 blue, & 1 pink & have no algae issues.

 

[Michigan Mike]

Use em they are great bulbs.

 

[tommyz44]

I run ATI 1 purple plus, 1 aquablue special, 1 blue +, and 1 UVL super actinic. After adding the purple plus i didnt see any increase in algae growth. IMO the puple plus looks more pinkish which really brings out reds in my zoas

 

[ramdude]

I have seen the ati purple in a fish store. I have not seen the fiji purple yet.

Which would people say is better to buy ? I am running 3 blue &1 10k right now.

 

[tommyz44]

I have not seen the Fiji purple either. Though i have seen good reviews on them. With your setup you could get rid of your 10k for a purple plus (or the fiji). I wouldnt mind getting a different bulb for my Aqua blue special the fiji gives enough white light.

An 8 bulb setup i saw the other day guy used 2 actninics 4 blue plus and 2 puple plus. Still looked like a clean white when the purple pluses were on.

 

[ReeferBatman]

Check out the spectrums needed for photosynthesis in corals (different than plants!!!).

Actinics provide the 'starter kick' to prompt phtosythetic activity, but not enough to actually let the photosythetic algae fully produce energy for the coral. You need a much higher peak for that, 10,000k lights will do it.

The Purple lights contain the same actinic spectrum as the true blue actinics but also provide some additional higher spectrum lighting. Still, I wouldn't rely on it solo for actual good coral growth, but if you already have your 10,000k spectrum covered you can swap or add a purple with no detriment. It's really just how you want it to look.


Ramdude - if you truly want to accelerate coral growth, replace a blue w/ a 10,000k. Truth be told you could even run 3 10k - 1 blue/purple for best growth rates. Your current setup minimizes the hump of spectrum that coral photosynthesis fully needs while instead them look friggen awesome instead with your 3 blues... It's a trade-off.

Tommy - The Purple lights do throw off a limited amount of the higher spectrum light needed but not enough to fulfill growth potential of the corals.

Throwing mostly Blue and Purple bulbs over your tank is like Having a supermodel girlfriend you only feed bread... She looks great, but your kinda starving her...

 

[ReeferBatman]

To the thread starter, if your other nutrients are in check, replacing an actinic blue bulb with a purple bulb will not create excess algae in your tank.

 

[ReeferBatman]

Here you go, hard Data for you.

A: Phototropic response; having a tendency to move in response to light. Basically this is the Chlorophyll containing plant or algae "moving" to respond to a positive light source to begin the process of photosynthesis (initial growth of plants, zooxanthellae, etc.).

B: Photosynthetic response; the process which begins when energy from light is absorbed by proteins called photosynthetic reaction centers that contain chlorophylls.

C: Chlorophyll synthesis is the chemical reactions and pathways by the plant hormone cytokinin soon after exposure to the correct Nanometers wave length (about 670 NM) of light resulting in the formation of chlorophyll, resulting in continued growth of a plant, algae, zooxanthellae and the ability to "feed" and propagate, and without this aspect PAR (670 NM light energy), zooxanthellae and plants cannot properly "feed" propagate. The results of the lack of this high PAR "spike" would be stunted freshwater plant growth, and eventually poor coral health in reef tanks."



In other words..
A) [420-500nm] Coral wakes up and turns toward light
B) [580-650nm] Photosynthetic Cells prep for final stage
C) [ 670-700nm] Coral 'food' actually created from Photosynthesis.


Now here is the Par spectrum of the Purple Bulb...

Enough to kickstart the photosynthesis process [and make it look uber pretty], but not enough to actually 'feed' the coral.

 

[keihi20]

So what your saying is that we need red (670-700nm) bulbs for coral growth?

 

[keihi20]

Blue and Purple bulbs over your tank is like Having a supermodel girlfriend you only feed bread... She looks great, but your kinda starving her...

Thats why I'm going through supermodel girlfriends so quickly

 

[tommyz44]

HAHAHA great analogy!

 

[ReeferBatman]

So what your saying is that we need red (670-700nm) bulbs for coral growth?

No, you actually need all 3 'bursts' of nm to feed the coral, not just the red...

But that is the most important part. Without it the coral cannot actually "feed".

The 10,000k T5's hit upon all the needed bursts of spectrum to let the coral feed through photosynthesis. But the extra actinic helps 'prep' the coral to more fully take advantage of the light available. I figure its a ~15-20% growth increase when actinics are applied in addition to the 10,000k bulbs...

But with only Actinics or Purple bulbs, your giving the [Coral] photosynthetic cells the dinner bell without the dinner.

The trade off is how nice your tank will look to people.

In my opinion, the best option is a 2/3rds ratio - 2/3rds 10,000k - 1/3rd Actinic

I have my actinic blue's wired on a separate timer... so i get the amazing look as well at morning and night... but during the day I'd rather give the corals food over aesthetics.

Don't forget T5's lose their intensity and lower their kelvin readings over time (losing the spectrum most needed for photosynthesis) and must be replaced every 6-9 months.

I just replaced mine after 9 months, and I suddenly got yellow coloration on my Prizm Favia!!

 

[Spyderturbo007]

Great question, as I was wondering about this as well. My AquaticLife came with a "Bonus Purple" T5 bulb instead of a 2nd Actinic that was labeled "to enhance coral color" or something similar. I just got finished cycling my tank so I obviously don't have any coral yet.

It has 2 x 10k, 1 x Actinic, 1 x Purple, so it sounds like I'm in good shape.