with tomatoes the red will promote elongation ... use blue light ... (6500 K) all the time ... that will keep your bloom locations tight ...
be certain when you spend your money on a cf you get the right one ..
- spectrum
- and size
you need to select a pretty large bulb ... maybe a 125 / but at least an 85 watt
I would recommend getting some quality nutes..... like a nice foxfarm organic 3 part .... that will allow you to control the plant more ...
hope that helps...