I did 21 Think Different and Auto Wappa's under 24 hours of light using 3 1000watt HPS. Yielded 6.4 pounds from them all together.... I ran 20/4 for the first 2 weeks though under MH then switched to HPS and 24 hours. Wouldn't do it again only because it cost me 540/month for electric on top of my 150.00 house bill
My bill is only 350 total now running 12/12 with photos but when I do my next auto grow I will do 18/6 or 20/4