Lighting LED and CalMag discussion.

[cres]

I hope this helps, I have been reading alot about high veg temps and humidity. One reason is I live in a High rh area and getting out the water is a problem.. Well the more I read the more I learn.. Just read today over and over to never put fans on your leaves... Always run fans under and over to control air movement, my fans have always been just circulating the room some on some off the plants.

With the addition of LED vs HID there is a need for increased cal/mag... why? Hazy has been doing his homework and very well maybe rewriting the parameters for auto growth. IMO he is well within the "range" as I am offten also in this range, and then fighting the humidity come flower. Where I'm running a dehumidifier non stop..(very expensive).

 

[cres]

Also wouldn't running a higher rh decrease transpiration? I think higher temps and lower rh would be better if the temp theory is correct..
A hydrated leaf would have a RH near 100%, just as the atmosphere on a rainy day would have. Any reduction in water in the atmosphere creates a gradient for water to move from the leaf to the atmosphere. The lower the RH, the less moist the atmosphere and thus, the greater the driving force for transpiration. When RH is high, the atmosphere contains more moisture, reducing the driving force for transpiration.

the more transpiration, the harder the plant is working the more lock out.

 

[evol]

But the theory is "because LED's don't give out the same radiant heat as HPS the plants don't transpire as they normally would, this in turn changes how the plant uptakes nutrients". Meaning you would want them to transpire more to reverse the affects of the LED not producing the same radient heat.

Wouldn't you want a slightly lower rh to balance it out?

 

[CLMonkey]

Thank you cres, that was an eye opener about how i have been keeping my grow.
I will have to get my Climate more stable before i torture any more little ladies.
:Stones slap:

 

[CLMonkey]

But the theory is "because LED's don't give out the same radiant heat as HPS the plants don't transpire as they normally would, this in turn changes how the plant uptakes nutrients". Meaning you would want them to transpire more to reverse the affects of the LED not producing the same radient heat.

Wouldn't you want a slightly lower rh to balance it out?

that's how i was seeing it evol. but my plants had the paper look and low RH long before i added my LED, so i wasnt sure.
all i can say is that i am running at 40 - 42%RH @ 78f daylight wich would be considered relatively low? and then at lights out it can drop to 60 - 65%RH @ as low as 65f during lights out. which is high. no wonder my girls are throwing in the towel on there own accord :/
I know for certain that this winter my RH will hit 25% if i let it because of my heat.. yay!
I'm going to read over it a couple more times, im kinda sloe like that.

 

[cres]

I'm not saying that one way is better to any other way. I'm just adding some current info I have run across. But I will add that when you grow with alot of lights.. 2000-8000w you need either ac or a very large air exchange, in which you cannot control rh. without ac. In my own experience I have run 85-90 temps with 60-90% rh in veg with no problems.

So I welcome hazy to test his theory, as I read many other growers doing the same.

 

[DABaracuss]

Well Now this is good..I didnt know why it was happening but the pieces to the puzzle are coming together..With my own grows ..I had cal/mag issues ..i started with a rh of around 80 and temps at 81 need to go back and look..But after i was reading ..I took out the heater and the humidifier out because the temps stayed 77-80 by itself.Then the cal/mag started.we had allot of rain and the rh went up and teps at 80 and growth was better for 2 days while the rain was here.:tiphat:the plant wants 100% rh the less it has to work for that the better.

 

[CGR]

:thread:.........

 

[evol]

I am very interested in seeing hazeys results also. I'm always down for experimentation but I still feel it has more to do with the intense red of LEDs or even some factor we arnt considering. I also believe silicon(such as pro tekt) used in conjunction with cal mag may negate these issues because my "team" and I have not had cal mag def with our nute schedule.
I have not done any real research in this matter I'm simply going from my own experience and using basic logic and reasoning. This subject does however intrigue me and I have been looking into it more.

 

[TaNg]

Just a word of warning guys high RH can kill LED lights,most LED failures are down to high RH and temps,at the very least you will get condensation on the lenses/optics.