20000k - 10000k

[drdrew]

i just changed out my 20000k DE 159 watt bulb with a new 10000k ushio.

 

very much color difference, as we would suspect.

 

i know the PAR should be better.....should i expect faster growth rates for zoos and sps?

[Reefer_Buddha]

do you have any actinic supplementation?

[drdrew]

no. do you?

[Dingo]

The general rule seems to be lower K, faster growth, less intense coral coloration.

 

I read a coral propagation article posted by Bird, I believe, that recommended using 6500K bulbs for fast grow-out, and a higher K bulb for coloring up prior to market.

[Reefer_Buddha]

ill be using a 10k ushio but will supplement with 2 36w actinic. With 20k you really dont need that but what dingo said covers it all.

[wetworx101]

that combo should be very nice.

 

"The general rule seems to be lower K, faster growth, less intense coral coloration.

 

I read a coral propagation article posted by Bird, I believe, that recommended using 6500K bulbs for fast grow-out, and a higher K bulb for coloring up prior to market." --Dingo

 

Just to point out, changing bulbs color has nothing to do with the color of the corals from the pigment standpoint. There is no "coloring in" phase with corals. I forget where I just read it...prolly in the myths part 3 article of reefkeeping magazine.

There is better PAR and growth with less K, peaking around 6500K, but less than that actually causes a loss in spectrum most needed for photosynthesis...it just goes yellow. So a 4000K is going to have less PAR then. PAR is really just measuring that "sweet-spot" somewhere in the middle.

[Dingo]

I disagree that the spectrum of lighting provided does not influence coral pigmentation. There is quite a bit of evidence that corals produce protective pigmentation in the presence of blue spectrum light.

 

Also, although I didn't say it, I agree with you that if you go too low on K, you end up with less useable light for photosynthesis.

[movingshadow]

I'd do it just for aesthetics...

 

I have 18W of PC actinic along with 70W 10.000K HQI on a 5.5... my corals love me...