Incandescent lamps are cheaper to buy but they throw off a lot of heat, they incur maintenance costs, you've got to duct away all of the heat, due to the heat they generate, they have to be kept well above the canopy height, and they use significantly more power than an of comparable output.
LED's are more expensive up front but they use far less power and, since they don't give off infra red light, they don't heat the plants the way an incandescent does so you can run your light at a low hang height, 12" being not uncommon.
The Covert light looks a lot like other lights that are sold by resellers - good features, nice spectrum, and can be daisy chained but the PPFD map is not as strong as other lights in this class.
PPFD = the number of photons (light particles) hitting a square meter every second. It's measured in micro moles (µmols). Think of it as an "inches of rain per hour" measurement.
Cannabis will absorb and use up to 800 to 1000 µmols of light. That's called the "light saturation point". The Covert light can generate about 900µmols across a 2' x 2' area in the center of the light. That's in
the PDF that you can download from
the product page. Once you get outside that, it's 600 on the sides and even less in the front, back, and corners. You should provide at least 500µmols to your cannabis plants. This light will do that in all places except for the corners. Those number look similar to other grow lights from resellers and you can grow a good crop with those numbers.
Research tells us that there is a linear relationship between light levels and plant quality, crop yield, and crop quality. Put another way, if you've got good genetics and if the rest of your grow is squared away, the more light you give cannabis, up to the light saturation point, the more weed you get.
With that in mind, in this price range and in the 4' x 4' class,
this light is hard to beat. If you look through those PPFD charts, what stands out is that the light put out an incredibly even light cast at all hang heights from 8" to 24". It's
really something.
I have no connection to Spider. My grow is in a 2' x 4' tent and I have bought 4 lights since I started growing, none of which are Spider Farmer brand. I just think they've done a great job with this light.