Question about 12 on and 12 off and lights

[lulu64]

When you switch to 12 on and 12 off do you also need to change the type of bulb. Is it necessary to go from daylight bulbs to warm light bulbs?

[Plantguardian]

If you're using florescents it's good to do if you can. That's basically what high intensity growers do when they switch from cool, blue-end MHs to the red/orange spectrum of the HPSs. So it's not necessary, but if you can afford to do it, it'll help a bit... or just add some more warmer spectrum lights in addition to what you're already using. You know what the say, the more light the better, right?

[Leonardo de Garden]

It is not a necessity, more a semi-common practice.