Hi guys. As topic says I'm moving from CFL to 400w HPS lamp in a few days. I had no experiance with HPS and I do believe that this topic was discussed million times, so just post a link to it and ill find out. How high HPS should be abovemy plants? i know there will be more temperature related conditions but how does it work in practical way? Shall i just hang the light as high as possible or should i adjust height like i do with CFL light when plant is getting bigger? Or there is somewhat sweetspot that was found ages ago?
Does your fixture have a plain winged reflector or a air cooled one? My 400w hps light is a plain one and during flowering i stick my hand on the canopy in the center of my light and if my hand gets too hot after like 10-20 seconds ill raise it up. its not very scientific but its been working for me. if its air cooled i cant help lol when its in veg ill raise it higher maybe between 24 and 30 inches.
Hmm. So that chart says 36,000 for a 400w bulb... my hps bulbs are rated at 50k. Sure they degrade after long hours of use but 28% less? Lol yeah right Just make sure you match your grow space with the bulb... aka not too big for it and don't burn your plants.
Why would you move from CFL to HPS, like trading in your 1985 Datsun for a Ford model T. You are taking a step back in time man, and you will certainly have heat issues that you didnt have with CFL. Go cob or quantum or Ceramic if you are dead set on arc lights.
CFL will be my veg room But i have not so much space for a lot of CFL lamps to achieve such wattage as HPS.