Usually HPS is used in flowering stage, altho some growers use it all the way...
The distance will depend on how cool can u keep the bulb, the coller u can get her the closer will u be able to put her on top of ur canopy, currently i have mine at about 18", plus 4 x 18w 6400k fluoro tubes in my grow room...and i dont have heat issues (so far)...
OmegaVermelho Reviewed by OmegaVermelho on . 400 Watt HPS question I have a 400watt HPS and i just want to know will this do for veg and for flower? and how far do i keep it away from the plants in both stages of growing. thanks Rating: 5