Yes, there was bad news after all, there's too much green in white light, you have to get 1/2 minus green filters. It sucks but what can you do? Fortunately they're reasonably priced and widely available. Turns out half minus green is just the right amount.
I run Area RWs to within 12 inches of the tops. I space 50 watt cobs out at about the same. You're trippin, bruh. What up wit dat?
HPS does put out more LPW but CMH does not until you get into 1000 watt DE units.but the higher lumen rating for HPS is due to the spectrum they produce and not higher efficiency.one thing this study shows is that spectrum matters.lumens or ppfd tell you nothing about spectrum. one way of telling how much light your plants can use from a light source is to look at how much intensity is required to produce signs of light stress like photo inhibition and fox tailing.plants grown under my T5s look the same as plants I grow in my patio during the summer.in spite of the fact that LED grow light makers have been making false negative claims about fluorescent from the beginning they are still the best selling grow lights in the country and the ones recommended by horticulturalist,greenhouse and garden center operators http://www.littlegreenhouse.com/guide3.shtml I studied electrical engineering in the 70's and design and build my own drivers for the lights I build to test and learned about horticulture by reading studies and talking to horticulturalist at the local garden centers. like a gardener at the university once told me "I don't understand all these fancy theories. I need to let my plants tell me what they need" there Is a lot we don't know about plants so it still pays to learn to listen to them. I'm sure there are enough new growers with the spread of medical and recreational cannabis who are seduced by technology to keep LED grow light makers in business.but all the false claims being made by grow light makers is not helping their industry. in my area electricity cost 9cents/kWh. and I run a total of 600watts in my flowering and vegging closets combined so an expensive grow light would not last long enough to pay for itself. lumen depreciation is another factor these companies do not like to talk about. cree gives their COBs a 35000 hr L85 rating.about the same as energy miser bulbs and you would need water cooling to maintain the 25c operating temperature that rating is based on. if you had studies semiconductor physics you would know that it's heat and not operating current that causes semiconductors to degrade
i didnt say CMH > HPS
more like >90% lumen rating at >61000 hours when run as high as 2100-2800 mA at 85-105C
I think DE's are taking over in light assist greenhouse gardening, but yes T-5's are for sure the best selling veg lamps world wide. As shitty as they fucking are with bulb changes, they sell like hot cakes. All one would have to do is call any hydro shop in the world and ask them how many T-5s you sold this week? They are so far from being obsolete if so funny to hear people say that!!!!! I think they are pieces of shit and i own 10 of them.
Agreed.
LOL! Damn, I gotta admit, that made me laugh!
Thanks, they do look low enough, at least the 90 cri, which may explain why LEDs at least appear to work better than HPS watt for watt. I'm pretty sure HPS has a lot more than that so maybe it really should be filtered.
BTW you know how some light companies add near UV LEDs to make people think it will increase potency and they'll sell more lights? Well ironically it would probably reduce growth, unless Cannabis is immune to it, which is possible, at least at low levels. Doubtful it does any good though, and is certainly a health risk.
I don't think that's true. The plant benefits from all the colours but not all are necessary even for CO2 uptake. CO2 uptake is regulated by stomatal contractions which is affected only by temperature and humidity afaik. Regardless of which color you provide, the end result is the same: electrons liberated from H2O are excited in the reaction center. The only difference between green light and any other is that green is responsible for fixation deeper within the tissue (where as blue fixes near the surface; red intermediate).
are we still talking about tomato plants?I don't think that's true. The plant benefits from all the colours but not all are necessary even for CO2 uptake. CO2 uptake is regulated by stomatal contractions which is affected only by temperature and humidity afaik. Regardless of which color you provide, the end result is the same: electrons liberated from H2O are excited in the reaction center. The only difference between green light and any other is that green is responsible for fixation deeper within the tissue (where as blue fixes near the surface; red intermediate).
