I'm growing my Canadian legal limit (4 plants), all White Widow X Jacky White from fem seeds. It cost me less than $300 Canadian dollars to adequately light the 25 square feet with over 33 watts per square foot (840 watts total right now). Not my first grow with these, or with this soil. The soil is getting better with each use. I'm using a water only from seed to harvest system. Just tap water, no pH measurements, no EC, no nute mixing, no teas. I'm incredibly lazy, just ask my wife!
Here they are today, exactly 28 days (4 weeks) from the flip to 12/12.
Peeking into one of the tent side doors: