Light temp question
 

I'm acquiring a CF light fixture from someone that currently has reef
bulbs; 2 10000Ks and 2 actinic, with 2 extra 10000Ks. I know the
actinics aren't useful for plant growth, but what about the 10000Ks? I
won't be able to get 6500K or 6700K bulbs for a while, but I've read
in a couple places that 10000Ks will promote bushy growth instead of
upward growth. Is this true? Also, I've never seen actinic bulbs in
use. How bright are they? Could they be used to simulate nocturnal
conditions?