Lighting - Best K

[alrha]

Which K is best for our corals?

A) i've heard opinions that the corals/fish only really use/see the 20K light as the lower levels are filtered out by the water and that is what they are used to in the ocean.

B) i've also heard opinions that they only use 10K light and that the 20K is really more just for show (for those who like a bluer light).

C) i've also heard that the sun's natural light is closer to the 5K area, which would lead me to believe that if we are trying to replicate the sun, we should use bulbs in that lower range (and perhaps supplement with 20K to keep the bluer look)

Let the discussion's begin...

 

[jackson6745]

IMO...as far as health goes, it really doesn't make a difference. I have kept the same corals under 10k ans 20k and they did fine under both. Many people have had corals for 3+ years under 400w radiums or 250w ushio's.....so, to comment to each statment

A) doesn't matter what they're used to, they adapt.

B) 20k are not for show, they do serve a function as well. If not many people would have dead corals under their 20k's

C) You would need LOTS of actinic supplementation to balance out the color of 5k's to more of a bluer look. It's easier and more efficient to use 10k, 14k, or 20k.

 

[glipper69]

water condition is far more important than anything else, corals will adjust to light in different ways, mostly by shifting their own color. I've found the that 20K's do enhance the color of coral far more than say a 10K but you also see a dramatically reduced growth rate with the 20K's.. so for myself who also has used ever bulb from a 10 to 14 to 20k i've finally settled on a 14K AquaConnect bulb, but I am planning on trying the 15K XM. which I hope is similar to the aquaconnect, but at a significantly reduced price.

good luck,
Frank

 

[jhale]

I have 2 175 10k's which appear very yellow, I also have 2x60" & 2x48" actinic vho's to balance them out.
I agree that coral will adapt to the different wave lengths. I assume that my coral which has been growing well thinks it's in a shallow reef and is getting sun filtered through only one foot of water. I'm planning on adding some 250w 14k's soon. They will be placed over the middle of the tank where there is no rock. This will be the deep area of my reef. All 20" of it. I'm planing on placing some sps, like stag's on the bottom. If possible I think it's good to give a mix of wave lengths.

 

[Pseudo]

I love my XM 20's. I get fantastic growth from it. But I am also using the 400 watters so it isn't that dull and get more par than the 250 SE bulbs. If I had the choice I would get the best of both worlds with the 14k or 15k XM's. I just replaced my XM but have a 14k AC sitting here for my next change in 4 months. The colors under the 20k's are better than the 10k's unless really supplemented with actinic lighting.

JMO

Kasei

 

[marrone]

I just changed to 14k Hamilton, after talking with Glipper69(Frank) about, them. I love the color whitish blue, though not completely burned in yet. I noticed under the Ishio 10k the coral were opened much larger and I had better growth but the tank was very yellow.

 

[bad coffee]

Corals grow better with light around 6500k, which is 'daylight' For the same wattage, 6500K puts out more PAR( which the corals use.) than a 10K or 20K

Ever see a LOA light over a tank? It looks Pee yellow. pardon the expression. I had one on my 4 gallon cube, and next to my 15 gallon with 10KK + blue it was downright UGLY.

The color of the light is more for our eyes than for the coral. As long as you have good intensity, the color temp realy doesn't matter to the coral.

I just ordered a 14K phoenix for my 150wDE. I've got a Ushio 20K right now and it is really blue.

BC

 

[glipper69]

If I had 400 watters I would definately use 20K's, but since I have only 250 watters I stick with the 14K

good luck
Frank

 

[alrha]

i find the 20Ks much dimmer and feel that the 10ks reflect a more natural color of what i would see if i was snorkeling.