Im doing a 2-3 plant scrog in a grow tent soon, and i can't decide whether to use a 400 watt hps/mh or whether to spend a bit more on some led lights so i don't have to worry about temperatures. Im just wondering how many watts of led and what colors i need to get the same results in yeild. Cheers in advance for any advice.
A 400 watt hps/mh will get you going way cheaper than any good LEDs that I know of. LED is a longer payoff kind of thing but you don't have to deal with even close to the same amount of heat as HID and the electric bill will be less. I'm having to add heat to my grow room. An example, for a LED two - three plant grow, I would use two Kessil H350 magentas which cost about $540 (growershouse). Cheaper electricity, less heat and no bulb to replace....but the cost up front is more. There are certainly other good brands but the good ones are NOT cheap. As far as wattage - 150 - 200 watts...and I mean real watts not just what the LEDs are theoretically capable of putting out for a few seconds before they burn out. For example, the two Kessils would be just shy of 180 real watts. Alternative thought - HO T5 - get a good fixture and some PAR lamps. Keep the light close (few inches kinda' close, just so it doesn't touch). It's cheaper than LED to start, and it's also low heat...not as low as LED but much lower than HID. It's cheaper on electric than HID but you do still need to replace lamps.
LEDs and florescent lamps don't use less electric power to harvest the same weight as HID lighting. Even having to cycle the ventilation more, the HID lamp will yield more per watt than any other type of lamp. The guys selling the LEDs are quick to lie about this unfortunate fact. If it was true we would have all switched over years ago. Most average folks can out think the cooling issues that goes along with HID grow lights. Few led lamps work worse than Kessils. Most folks toss them after the first grow, a few will add additional lighting (CFLs or HIDs) so it won't seem like a complete waste of $500. Kessils work great..... for lighting a walkway or expensive Christmas decor.
I veg under HO T5s, then move them into the flower tent to flower under HPS. 18 hours under a 500 watt MH vs 18 hours under around 150 watts of T5s = ching ching money savings. I haven't seen any difference in yield.
I have direct experience with Kessils and I can tell you that you that they are not "shit" from my own experience. You might try to be less insulting on the little information that you possess. There are quite a few documented grows of 1 gram+ per watt on LEDs only. Do some more research before you buy.
They have quite a few good LED lamps you can buy that will grow some nice bud, Kessils are not one of them. You want to buy some used ones real cheap? Lots of folks selling them (only slightly used). Small spot lights don't seem to be able to grow much more than some holiday spirit attached to a Christmas tree. Few things tell less about a grow than "grams per watt". "Joe was not real good at mixing nutrients. He had to veg for a year and harvested a pound of low quality bud." "Jim was an expert grower. He harvested a pound of high quality bud in 85 days (clone to harvest)" Both have the same gram per watt ratio, except Jim used 25% of the power that Joe did. So all you Joes bragging about gram per watt ratio can save it for someone who does not know better. Dont listen to biased research from lamp salesmen. I would be willing to read your unbiased LED research and view your huge harvest pictures. Links to mine are in my sig.
Any metric can be challenged that it doesn't tell it all. No single one does. I haven't spent any time bragging. Only you have. I refrained from calling someone's recommendation "shit". Others didn't. Obviously, you think that is good behavior and I'll ignore anything you have to say in the future which will I'm sure save me much aggravation and bad advice from you. Thanks for letting me know who you are.
Don't get all mad when someone challenges your advice. That is what a forum is for (dialog). Keep an open mind, it will make you a better grower. Now and then, you will find someone who knows something you don't. No one is judging you for being a new grower, we welcome you my brotha. Best to not ignore the truth and keep an open mind. Peace, R.
How much faster? I wouldn't mind being a week behind, rather that pay to run an MH for 18 hours per day.
lol, nothing is free, you won't save a dime but you can make it take longer by using less watts or less effective lighting. I would rather pay the same and do it quick... But some folks have a lot of time to veg (flower room is busy), so using less effective T5s seem to work out real nice time wise.