One of my first gardens was a 400 watt HPS, but one of the plants got really tall. I added a 125CFL self ballasted grow light, and it was difinetly worth the cash. All you need is a special cord that is available at your grow store to accomodate the large base of the self ballasted CFL, about $20 or less and the light is less than $35 if you shop around. Good luck, I hung mine vertical because i had to, but it worked great.
mmjman Reviewed by mmjman on . Adding CFLs Below Canopy to Supplement 400HPS Scrog? Oops, I meant tube fluorescents, not CFLs. I use the Scrog method (36" x 48" screen) under 400w HPS due to low overhead clearance of the space. I've had good success so far but have been toying with the idea of upping the lighting. It was suggested to me rather than purchase a new lamp/fixture with more balls to simply add more light to what I already have. This got me thinking of the four 4' T12 Ott-Lites I've had in storage for years, and I'd like to add them to the system. Their Rating: 5