grow rates vs kelvin rating

[ihavtats29]

im just curious who is getting the best grow rates under diferant kelvin ratings, first i had some 175 watt blueline 14 k superblue bulbs and had some noticable growth on all my corals, 1 bulb started to red out and i was given 8 bulbs with 4 months use on them ranging from 20k to 10k all are xm i ran the 20k for 2 months now i ive seen a little growth but not as much as i was getting from the 14 k blue line bulbs i just switch over to 14k just to see if i get a growth diferance over the same amount of time,also my blue tort went from bule to a redish brown in color but is now starting to improve back to blue.

[DaveJ]

Higher Kelvin at the same wattage will reduce growth... it may increase coloration as well, but you'll see less growth. Typically people up their wattage if they want to go with the higher Kelvin bulbs to maintain the same growth. Growth is spurred by PAR, the lower the K the higher the PAR typically. To offset the lower PAR of the high K, you up the wattage or the time you run the bulbs.

Corals will adjust to new lighting conditions and if they are healthy will return to their regular coloration or even shift to something new. So long as they don't bleach, you should be fine.

[ihavtats29]

they are all very healthy with great polup extention, very full looking id just like to see better growth rate from them, 90% are 2'' frags. thanks for the response

[NealNano]

Got with 19ks for fast growth. You wont get the same color but your frags will grow fast.Then you can use 20ks after you get the growth you want. Or go in between with the 14k color will be good as will growth. Do what will work for you. I run 20ks but want my frags to grow out, but I dont want to lose color. I will be going to 14ks as a compromise.

[cnaegler]

I use three 400 watt xm 20k's. Didn't like my growth rate so i added four VHO's, 2-10k's and 2- actinics, and it definitely picked up the growth and the colors are much better. I attribute that to the 10k's.

[crmjacks]

it all depends on the coloration and species of coral in question. those higher up on the reef are used to more yellow light, those deeper used attenuated light closer to 20K. IME 10K does give better growth, but less preferential viewing color.