I bought a few LED grow lights a few months ago.
Here is the REAL deal:
90w or 100w of LED does not replace a 400w sodium. You should calculate how much HPS or florescent you would use something in that ballpark, maybe 150w of LED = 175W HPS.
LED Panels made with traditional led's:
I purchased some of those 14w panels and they are a joke, but what do you expect for 14w. They hardly do anything and produce too little light to do anything other than supplement a HPS lamp, not replace it!
UFO & other 90w to 300w LED grow lights:
I got a 90w UFO light and put it in one of those 1.7"x1.7"x4" grow tents. Now that grew my plants! unlike the 14w panel this one seemed really bright. The light was not a 400w sodium but more like a 100w sodium. This thing about the LED's not being bright to the human eye but bright to plants, that is bull shit. The LED lights that my plants liked were the ones that looked really bright to my eye. Unfortunatly after 3 months my UFO light broke, thank god I did not buy it from some e-bay store that is no longer around to help me with the warenty. Yet I did have to scramble to get other lights in my tent. So I give a thumbs down to the UFO because they are too expencive to be unreliable, I think its that built in power supply not the LED's that went bad. The UFO had another unexpected downside, it was not silent, much louder than my ballast used to be, it needs a cooling fan! Also when my UFO broke I looked inside, the way these are made is a huge number of leds are built right on to a big heatsink, then there are power transformers and 3 cooling fans inside. It looked like the light did not hold up well in the humid environmet inside my tent.
High Power LED Panels:
I also bought some of those 50w high power LED panels for $150 each, finally a LED light that was worth the money. This did not replace my HPS, but I had my setup in a closet and cloning area above it, the cloning area got too hot to put a lot of florecents, but I had extra space. So I mounted 1 of these to the wall next to the rooted cutings that were growing slowly. They started to grow really fast! Since they produced no heat and no sound and good light I was able to transform a slow growing area next to my cloinging area in to a fast growing area. Oh and when the UFO broke I was able to put the 50w led panel on top of the tent and zip-tie 4 20w florecents to the corners and it is better than the UFO alone.
I have not tried flowering with LED's.
