This is the set-up from last winter. It's 414 watts worth of bulbs. I use 18/6500K for vegging and 18/2700K for flowering. My box is a lowly 4x2x2 foot POS but it held four 2.5 gallon pots tightly especially with fans, heater, bottom heating mats and so on. One thing for sure is I have a lot of stuff plugged in. (ARG).
I was gonna upgrade to a bigger box but the more I thought about it I am ready to fire it up for my fruity chronic juice seeds in 20 minutes and I don't have to spend a dime. It's been sprayed with bleach and cleaned up so I'm ready as soon as I finish messing with the outdoor crop.
"Maybe" next season I will "up-grade" or even move up to a couple of 400 watt MH/HPS set-ups but I'll tell you that the FIVE zips of great Master Kush bud I got off of four plants was a true epiphany!!! One of the best parts was it was fun running home from work to check on and mess with them.
Two-way splitters are great but kick me in the balls if the 10 inch flexible socket extensions and not the best thing since sliced bread. They just put the light right where you want it. Just looking at my pics makes me want to pull the trigger now. The last grow was my first indoor one and if things work out as well this time ...