a blackstar easily can pull over a gram per watt, my kessil grow was just ridonculous on 3 of em spread over a 2x3ft table blackstar was also grown over a 2x3 ebb and flow table, with the many mistakes that my partner made such as not raping the bugs he got, and packing the table too full of plants so i didnt get big enough root systems to pump out the yeild i wanted and i still avereaged between 5-7 zips on every run and i ran each way 3 times for a total of six runs. The reason i keep going back and forth between kessil and blackstar is price and modularity. being able to properly spread your light out will give you way more nug than getting a bigger light that puts out more light. Reflective material and proper light placement is the most important thing with an LED. If you take care of those two things i can easily see a 240w blackstar pumping out 8 zips of some good, you would have to scrog a single plant but its doable on a everyday basis. Mind you my partner was a complete idiot and i only came by 3 times the entire cycle of each crop beginning middle and end. So i barely did shit but provide equipment and advice that i learned here and from my older friends that have been doing hydro for 20 years. If he had followed what was layed out on the forum and by my friends he woulda pulled way more for us, he used too much nutrients, didnt kill off the fungus gnat larvae in the roots or the spider mites. I still got more than a gram a watt with those shit conditions.
Believe me, dont believe me say im full of shit it doesnt bother me any more i've grown tired of the constant debate between led and HID lighting when its so obvious that when grown scrog style an led will always beat out an hps if its a quality unit. If your growing hydro inside you shouldnt be doing anything but scrog, any other way i see as hurting yeild. Theres more than one way to skin a cat and thats just my opinion that scrog is a better method but its the only way to grow with LED's.
To those who say a 240w blackstar is not equal to a 400w hps ur right in the amount of watts used its no where close, however plant growth says that its a much better light than any 400w hps will ever be. My plants grow more stacked, faster, denser nug, more trich's, better definition in the shape of the nug everything is better with my LED than my 400w hps was except yield it stayed the same sort of give or take a few grams on the high and low side from small environmental factors. When you factor in the amount of ventilation you need to run a proper hps setup you will start to realize that 250 bucks for a 240w panel is not shit sure you may get a pos 600w hps for same price but what happens now you need a 200$ can fan to evac the light fixture and another slightly cheaper fan to evac ur room, i could have 2 panels that would be pumpin out more buds than a 600w would for less $ initially spent because of all the venting the hps takes to run. It cost me 40 bucks to ventilate my cab and i evac the whole cab of all air in less than 30 seconds.
The kessils are a bit hotter than the blackstar but that is not a real big deal not hot enough to worry about.
Ive been forever converted to LED's i still use my hps's just very rarely and when i need to expand and cant afford a new panel right this second because i still have all the venting equipment from before converting over. Wish i had never spent that money i would have way more led's than i have now and be spending so much less to get what im gettin now.
I've been looking at those Kessils for quite a while now. But @ $200 + for just 36 watts.... I'd need like 3 of them for one of my small cabs.
It is one of the very few LEDs where I seen people exceed 1 gram per watt (though the gpw is not totally accurate way to determine yield, it still gives you an idea..). There's a thread on here somewhere with that grow, some Australian guy I believe. I'll have to see if I can't find it...
What kind of heat do the Kessils put off?