3x3 lighting

I’m just curious on the most efficient light to keep a mother or possibly 2 mothers going .. to keep em nice green and vegged .. monthly costs ? I’ll most likely be using my old 3x3 .. also . Is it better to keep mothers on 18/6? or run em 24 ? I’m new to this page . But I know there’s lots of...

Looking for suggestions on budget LEDs, COBs or quantum boards with decent efficiency? Looking for about 15% blue in the spectrum.

I need some educated advice on what type of led to run in my 3x3x6 tent. I'm currently using a 400 watt cmh light but I want to cut down my electrical costs. Any help is appreciated!