EDIT if you want to skip the LED bashing and get to the metal halide / mercury vapor loving, and why you NEED MH or MV (and NOT HPS) skip to the middle. Also 600w mh bulbs ( non conversion ) are available.
I don't see the exaggeration? The LED's that are good are only being researched recently to the tune of millions of dollars.
I've followed so many LED grows and LED companies new offerings.
I think the most exciting thing about LED's is the fact that the research IS going on, and they are making new materials than can survive the cooling/shrinking process. Very high tech stuff, NOT CHEAP.
The reason alot of LED's are junk is because they overpower the diodes to produce more light, thus making them useless really fast because they deteriorate quickly. Also the ones that aren't overpowered definately wont be comparable to any metal halide, mercury vapor, or plasma bulbs (hps sucks).
The only exciting thing about LED's is the fact that the good ones will be cheap in the next 20 years, SHOW ME A LED GROW WITH NO SUPPLEMENTAL LIGHTING THAT OUTPERFORMS MH, MV, or Plasma lighting.
Also the LED'S that are higher wattage produce ALOT of heat, which alot of people don't know...
Yes LED's can put out a good concentration of a particular spectrum but there penetration sure sucks and if you had to purchase enough LED's to cover ur grow you would be out thousands and thats EVEN BUYING THE GARBAGE LED's THAT ARE AVAILABLE NOW. and even after that you still can't do a good flowering with them, theres no UVB LED'S at this point because when the chip cools it cracks or the lights deteroriate too fast, thats why millions is being spent on research but they HAVE figured it out, it's just gonna cost millions to buy the technology at this point...
Anyways go ahead and buy the LED's then and come back to us and tell us how it goes, then do the same grow again with MH lights and we will see what the scoop is.
I do believe the future is infact LED's or plasma / induction lighting or a combination of them all.
EDIT - want dank nugs with tasty crystals? Don't use LED's
EDIT Some better alternatives than led's - phillips ceramic metal halide 400w (needs hps ballast but if u buy it from the retailer its got lifetime warranty and its cheap)
Mercury Vapor bulbs on ebay - produce alot of UVB/UVA and being sold dirt cheap because they are being phased out, alot of lower wattages like 100w 175w 200w 250w etc... You dont get many lumans but the radiation the plant recieves is going to be wonderful
Solarmax 1000w mh (7.2 (or 7.4 cant remember)kelvin) - can be had on ebay for $80 and if you call the guy from texas (world of hydroponics) he will cut you a better deal if u call, these bulbs mimic hortilux blue's
solarmax 600w mh conversion bulb -same deal but more expensive than the 1000w LOL
don't buy digilux metal halide bulbs (5.5 kelvin), they produce !!!!NO UVB!!! they are the same spectrum as the cheaper maxlume bulbs(5.5 kelvin) (also made by cap) but reinforced to take the beating of the digiballasts (from caps rep's mouth). You are better off to buy two or 3 maxlumes and take the risk of them failing earlier (from caps rep's mouth). The cap rep also recommended to me to try ushio instead because they are a higher quality bulb!!!!!!
sunpulse 3k bulbs (replaces HPS) alot of guys claim to run a 10,000k bulb and a 3,000k bulb from sunpulse and never use HPS and go from veg to flower like that and have great results and I BELIEVE THEM, some also use the 6.4k bulb and the 3k bulb with good results as well.
Personally I've seen a plant vegged and flowered with mh , and a plant that was vegged with led's and supplemental lighting (still flowered in mh), and the plant that was vegged under mh was larger, and more potent (my guess is that since it was getting UVB from the beginning the plant new to create more trichromes during flowering) These were the same strain at the same time from clones, same nutes different veg room.
HPS is one of the biggest scams i've ever seen in my life dude... I tried hps alone, mixing hps with mh, and hps / cfl combo's and everything under the sun with an HPS (eye hortilux version super hps, the best right?). And the plants grew like shit, every time the hps was on it stunted their growth whether mh was going as well or not. Theoretically now I flower all MH's. The hps light can go past the beneficial 680NM far red light, and that causes plants to get confused and suffer. Also there is ZERO UVB from a hps bulb (UVB photon is the only thing that will make a plant realize its true potential).
Theoretically, I took all the hps bulbs out of my friends place and replaced with metal halide bulbs. I am not just preaching.
HPS is good for increasing bud size (some claim MH alone without HPS produces bigger denser nugs,and even running hps supplementally is bad, and I agree with them). but HPS is not gonna give connasieur nugs
For a supplemental light i'm looking into tanning bulbs from osram that produce alot of uvb, the trick is to supply the uvb amounts incrementally (if you are using a STRONG UVB supplemental light) with a very low amount in the morning, and around noon it increases and 1pm its nearing maximum and then slowly coming back down ( I can't find the chart but its useless unless u have a UVB meter anyways). Even the best MH bulbs dont produce enough UVB that you need them to limit them though, they actually produce very little but its better than none like a HPS. It's only when adding external strong UVB u need to worry about limiting it. For smaller grows theres a thing called a megaray, but with the price of MV lights on ebay i might just pick up a few of those until I can get my tanning lights....
UVB output is greatly diminished from high uvb output bulbs after even 6months of use and most is gone after a year or so, so it's best to start off with something strong because when its reaching the end of its life it will still be useful to you.