unclenedsfishfactory.com

Hi Ned,
A quick question, I have a 38 gallon planted tank. I have a 36" power compact lighting unit, one bulb is a 10,000k daylight, and the other one is 10,000 actinic. Each bulb is 96 watts. My question is will I have increased plant growth if I have two daylight bulbs instead of one actinic, or two actinics? Any advice would be greatly appreciated ! Thanks alot

some debate about that

some people tell me the light color doesn't matter
but generally most plant people seem to like about 8K
so typically they use a 6700 bulb mixed with a 10K bulb

algae certainly prefers blue (actinic) light (14K, 20K)
which is why we need it in a reef tank

the lower the number
the more orange , red , and yellow

the higher the number
the more blue and purple

supposedly plants prefer more orange
corals prefer more blue

plant tanks typically want 2 - 3.5 watts per gallon

coral reef tanks want 3.5 - 7.5 watts per gallon

you have 5 watts per gallon (enough for a reef)
you might want to cut back the hours on
...say 6 or 8 hours on as opposed to 10 or 13