I notice when I put 4 10,000K VHO 110W over my 55G it seems much brighter than when I change one of them for an atinic. Do I really NEED to use an atinic?
Thats because a daylight bulb on average is 3 times as intense as a blue bulb. While the spectrum emitted by those blue bulbs does benefit Photosynthesis, your 10K bulb out to have similar peaks in that 420nm section of the color spectrum. It's doubtful you'd see any real benefit from adding more blue. IMO if you did I'd say it's most likely a placebo effect.