Top dressed @ transplant, used a handful of Espoma @ flower.
Not feeding heavy at all.
The VPD graphs I have seen, I have to presume, are plotting leaf temperature against RH.
If we think sodium, the leaf temperature could be higher than the surrounding air. You have seen a hot drink in a cold place steaming away.
If we look at leds, the leaf will be colder than the surrounding air, as it is basically sweating. Does the hot drink steam so much, when the air around it is hotter than the beverage.
K is a common enough deficiency. It's involvement with stomata opening, and thus plant cooling, is where we see it lacking. With the leaf extremities torching. Under led, I have heard people talk on N,P,Ca and mg deficiencies. All the main ones except for K.
These graphs of temp V RH are not telling us our VPD under led lights, in my opinion. I have just exploited the virtues of leds, and got my RH up into the magic zone, where I couldn't reach with my hid's. Plants hated it. Couldn't drink. Sat there draining every bit of feed from the fertigation, and stripping the Ca+mg cations from the coco to. Fertigating at ec 2.1 wasn't enough, because I couldn't get a second fertigation to them before the food run out. They would of been permanently wet through.
This is just this weeks thoughts on the subject, as I evolve my methods of led growing. While using mainstream examples of what else should work. My plants turned a huge corner when I dropped the RH, from omg that's shit, to ain't that lovely. With a 10% drop in RH. Though that might not be the only significant change, as I'm battling on a few fronts.
That's odd.. was it typical burning right at the edge? I really didn't expect to hear of a K problem. In my mind I'm formulating a new feed, and K was reduced to help Ca and mg find a place on my coco. It seems led growers have found every problem possible now. With the usual spread of results. Leaving only the requirement for 'more' as a common denominator. Though even that wasn't found by everybody.
I guess by your double trial that this wasn't at the end of flower, when K has other uses.
My brain hurts thinking how you were burning up with just leds and a typical K level. Such freak results are often excluded from trial results as anomalies, but coming from you, I have to listen.
Curious, who has a cool and dry flowering environment with their LEDs??
Cool and dry conditions suck for soil, since the microherd much prefers warmer days, but it's what I use with hydro. The transpiration rate is decently high. Normally, this high of a transpiration rate, combined with a full pH swing, allows me to keep the feed strength rather low.
That's odd.. was it typical burning right at the edge? I really didn't expect to hear of a K problem. In my mind I'm formulating a new feed, and K was reduced to help Ca and mg find a place on my coco. It seems led growers have found every problem possible now. With the usual spread of results. Leaving only the requirement for 'more' as a common denominator. Though even that wasn't found by everybody.
I guess by your double trial that this wasn't at the end of flower, when K has other uses.
My brain hurts thinking how you were burning up with just leds and a typical K level. Such freak results are often excluded from trial results as anomalies, but coming from you, I have to listen.
great thread.
Im about to start using an LED for the first time. An Illuminar Il8, which is supposed to compete with the new fluence lights.
From what I was told by the sales rep, is you want to keep the lights as close to the canopy as possible, but reading this thread it seems that is asking for problems.
So you guys are running these as high or higher over the canopy than DE HPS'? Ive been wondering if its better to run them at 100% and put them higher or dim them down and try to get them as close as possible without issues.
Will actually be using a DE HPS along with the LED for now. Thought It would be casting a shadow over the canopy due to being higher than the LED but if I could run them at a similar height that would fix that issue.