Hi, Steve,

I am sure this has been discussed many times before. I use fluorescents because I have been using them for many years and I have them on hand. LEDs have been making a lot of progress, and some cars use them for headlights.

Not everyone would agree, but I think you should make the decision based on cost. A 40-watt fluorescent lamp puts out about 2800 lumens and a 37 mW "Superbright" white LED puts out about 0.2 lumens. I don't know what the LEDs are currently selling for, but my 4-foot fluorescent tubes cost about $3 each. You would need about 14 thousand of those LEDs for the same light output. I don't know if you could get that many of those LEDs for $3, but I kind of doubt it.

However, this is one of those questions that calls for a second opinion, and a third opinion, and so on. And cost might not be the deciding criterion for some people. LEDs do have advantages in heat generation, safety, low interference, etc.

ZM

You need to figure out what exactly you need these lights "to do". If they are going to be for year round growth (not seedling or low light requirements) you're going to fork out some serious dough to cover that large of an area with LEDs. For example most "reputable" LED grow companies have fixtures that cover around 3'x3' and are around $250 - $500. You will save money vs HPS or MH when it comes to power consumption though and they last a long time without needing bulb replacement.

I use a lot of Fluorescent fixtures and a couple of LED UFO cheapies from eBay. The results with the LEDs alone were pretty significant for me, enough that I want to go full LED. I use my cheap LEDs right now to supplement or to grow from seed with my Fluros.

I think the LED topic NEEDS to be brought up regularly as the technology seems to change monthly. Junk fixtures that use to cost $500 years ago are going for under $100 now.

One complaint I have about LEDs is the color they put out. My grow room is habitable with the Fluorescents but when I turn on only my LEDs it's not easy on the eyes and I can only spend a few minutes in there.

A couple of common conceptions bother me.
-LED is better wavelength
-LED is much more efficient

The manufacturers have to include several LED wavelength types because the wavelength is so narrow. This reduces efficiency and makes it hard on humans as the previous nick suggested and creates gaps in the spectrum.

I prefer to use an LED that's about 4000K which is similar to MH for hitting shadowed areas.

The best Cree LED's (CXA2540) only have an efficacy of about 130 lumens per watt.

HPS has a similar efficacy since I can get 90000 lumens out of 650 watts including ballast.

When you consider that HPS will provide lumen spikes in the UV range it's even more efficient. (SolarStorm recently added UV fluorescents to their LED lights.)

Look at the facts - not the hype. I use T5, MH, HPS and LED.

i am so glad for the discussion on leds..from my reading..
one thing leds have going for them over..the MH,HPS is..you can set up your led fixture with the specific light spectrum you need..avoiding UV,IR light..and green spectrum light.which plants dont make use of..
for me..i want more blue spectrum ... vegetative growth..
those that are looking to get there orchids/whatever to bloom would want more red spectrum..
i agree with whats been said here already.. ya gotta compare apples to apples..and avoid otherwise..
hope to see more show up !!! much thanks..