I have a 600 watt hps running in a 40"X40"X80" grow tent. The light is air cooled and I have no heat issues. I've seen so many different things anywhere from 10" to 5ft.
best is leave your temp gauge at leaf height and adjust hi or lo to maintain 77f/25c after 15mins as each grow is so different good luck
My 1000w HPS is permanently mounted to the top of my 5x5 tent. The plants grow into their "sweet spot"
I am the king of hps on this website . So your in good hands here . First you said air cooled . So you can put your hand under the light . This is the test . Make sure you not high or drunk at this time . You can wait 5 before you do . I think you can ?? lol Ok Put your hand under the light . I want to say about 8 inches away to start . Its the best height for the 600 hps lights . Also you should have a fan blowing over the top of the plants . So your hand is under the light . Leave it there for a few minutes . Can you leave it there all day with out getting it more then just warm ? If yes then that is your height . I want you to start with 12 inches first . Do my test its needed . Watch the plants . Check in 4 hours No leafs twisting then go a bit closer . Check again . Keep doing so to the 8 inch mark . Then check daily . And do not for get to raise lights daily with plant growth !!! lol. I was know to have buds hitting the glass all the time . Just the top of the bud got a bit burnt . And so you know a inch adjustment is CRITICAL in getting max yields with hps . a differece from 8 inchs to 12 or 4 inchs is about 30000 lumens lost or gained . OR 550 par , More questions ask. I do not advice any upgrades to your hps bulbs or hoods Or ballsts The tech is garbage today. I am not bashing you . I just finally got my system totally upgrade this week with Led And my wallet it hurting me . No lobster for me for 2 months . Extra bonus info . 400 watt viparspectra p series used facebook 80 bucks . LUMENS . 80k over a two foot by 4 foot area . 600 hps 80k lumes about 6 inches from the glass . Less then one foot squared . Think about that . It will take over 3000 watts of hps to get the same as a 400 wall led ! into the 4/2 area lmao. But 3000 watts hps spread will for sure pull a shit load more yield . So im comparing apples to oranges Point of my extra info led will pull more yield . In smaller spaces .
I can't seem to find the one of the many articles I have read lately but I'll try to get to the general idea I had got from it, it was written by someone much smarter then me. The author was doing research for a medical company. They took 3 types of lighting, HPS and led and not sure on the 3rd. He kept all 3 chambers at same temps and all that and kept lumens and par within the same ranges. After 3 cycles the hps grew faster and yielded more dried flower every time. The led had higher percentage of THC and CBD, and others that weren't present in the flower grown with HPS. It went into a lot more scientific wording so I could have missed, or misunderstood something. Curious if you have witnessed or noticed anything resembling this? I ask because I would think this would make a big difference in light selection if I'm sacrificing quality for quantities. It's also possible it's so minimal amount of difference wouldn't been noticed by the average hobby grower. Bummer I can't find the article. Sent from my BE2028 using Grasscity Forum mobile app
Many expert and thoughtful opinions thus far; I run with low end systems (UFO, COB, and SMD units) in seven different enclosures. Like JoeBlow, I keep my lights at ceiling level and try to work with the space I have available. Early on raising plants but soon a complicated network of folder clips and pipe cleaners spread things out and force competition among lateral branches to promote as much lower growth as possible before the flip. During veg I keep them between 8 to 24 inches from lights and in flower that drops to 4 to 10. Everyone finds the groove that suits them but the most valuable lesson I learned is to establish adequate drainage to prevent over watering and provide airflow to strengthen stalks. Pressure training ,i.e. super cropping helps to slow the more aggressive strands and lets others move towards evening out the playing field.
Now of that a rticle was older then three or so years its not up to date with these new panels . These new panels are spanking hps bulbs . I wonder if that article you read was about older led that were pink or purple in color . In that situation i would agree with the article you read . Hands down these new boards are spanking hps in everyway
Yea i a sked the guy why so cheap ? He was in a trance or cracked out on something idk . I did not care threw my money down and ran with the light . Also here i am finding the p2000 serires for 50 bucks on craigs list and facebook market . I bought three of them. I found spider farms the ones with four panels 100 each. I bought four of them. keep in mind used . But its so cheap . I think a lot of these growers are failed growers . And a lot of them are what i call raided specals . The cops come bust them and there desperate for cash lawyer fees so on .. I used to cash in on thosse deals I could buy thoudands of dollars supplies for cheap. Relist them and sell them . Mostly for a hobby I like to talk to growers for fun .
Very possible it was a dated article. Trying to learn as much as possible. The hieghts can be wierd for LEDs like the ones I have that don't have intensities to adjust. Get par adjusted for seedlings then my lumens are sitting at about 30k. I have some cheaper led lights mostly white but I can get it dialed in for lower lumen and par. It's quite exhausting researching so it's time to just do it and find that sweet spot. Thanks for the response, sorry if I got too of topic. Sent from my BE2028 using Grasscity Forum mobile app
after reading this i decided to lower my light. I thought i'd try what you said and lower it based on temperature, I check my plants every day or 2 so i will see how they react. I wonder if thats what stunted my auto flowers and delayed there flowering