LED and Calmag issues.

[buyyouabeer]

I've been wondering if some how the LED is disssociating the H2O into H2 and O2 gasses which is keeping RH low?

That would be a pretty explosive breakthrough LOL. It takes an assload of energy to break that bond; more than you get from the resulting gases, so no.

 

[ChiefRunningPhist]

That would be a pretty explosive breakthrough LOL. It takes an assload of energy to break that bond; more than you get from the resulting gases, so no.

I'm not sure I'm understanding, lol, and idk, just an idea.

 

[meangreengrowinmachine]

how do we reconcile the need for this higher heat and humidity, with the possibility for bud rot late in flower?? or is this something we just have to consider early on and deal with the consequences of the lower humidity later in flower??

 

[buyyouabeer]

I'm not sure I'm understanding, lol, and idk, just an idea.

No worries. If you had hydrogen and oxygen in your grow space you could have quite the explosion, think space shuttle Challenger accident.

 

[meangreengrowinmachine]

In all these spectrum charts the range between 780 and 1000nm are missing but most of these bulbs have another spike in the range between 800 and 850nm which is almost only heat. So those SPD's doesn't show the whole spectrum the only show the plant usable spectrum.

More than 12% blue would probably only keep the plants smaller and because you get less photons from blue its counter productive to add more blue. With red you get twice as much plant usable photons and 8-10% blue is enough for healthy growth. The blue is not bad at all but using too much is simply inefficient when you try to create as much photons as possible with a minimum of energy.

When you compare CRI80 and 90 CRI80 is more efficient in creating photons so normally you would expect better yield with CRI80. But its not the case. If you compare the spectrums CRI80 peaks at 605nm and CRI90 ~630nm. Under the mccree curve you see both frequencies are used to almost the same degree(maybe 98 vs 99%) which means plants can use both photons in the same way with almost the same efficiency.
Whats left are the wavelength outside the PAR range(+700nm) and here you see a significant difference cuz CRI90 has almost twice as much far-red. Far-red not only heats the leaves up more it has also other beneficial effects.(Emerson effect, shortened flowering stage, evens out PS-I and PS-II, ...) Believe me, its the far-red which makes the difference.

Unfortunately, I do not have enough time to discuss here and also via pm's. There are many others who ask me questions and only to discuss with you would be unfair. If you break up each answer apart and ask 10 new things we will not get any further. As I said, I'm not a professor, I do not even have a higher education. I've worked hard for my knowledge and I'm happy to share it, but at some point it has to be good.

Don't feel pissed, bro! I've simply not enough time for that.

I think this is something that I experienced and I was very lucky in that I have been using SIPs and organics so it was a lot more forgiving... if I was using a nute regimen this would have driven me NUTS... as it is.... I very excited to have set my humidity on my controller (yes I already have one since I grow inside in a the winter where it is very cold outside so it gets very dry inside) at 71% and temps at 71F (which is probably lower then it should be if I really wanted to have the growth I should)... I am very interested in my other question however on the flowering vs humidity question.. but this is some information I have been looking for forever!!! THANK YOU!!

 

[ChiefRunningPhist]

Under white LED the typ. leaf temp stabilzed is almost the same like the ambient temps. It takes a while and after 2h you can still measure -1 less but another few hours later the difference is less than 1°C in my cab. If you cool your room down to 25°C you would also get leaf temps ~24-25°C and you could stay with the 55% but what happens?
Lets say it with a picture..
I'm sure you've seen it already and have just forgot it but if you look closer it makes clear why we want LST near 30°C.
View attachment 4303241
As you can see, a plant getting 1500μMol/s/m² at 20°C grows slower like the same plant getting only 500μMol/s/m² at 30°C. That means that leaf temps and ambient temps are important factors for plants to run their metabolisms at a higher rate. With only 25°C you would slow down the grows rates. You would probably not even beat HPS results because of the blocked growth potential. At 1500μMol/s there is a huge difference between 25 and 30°C and you would waste light and energy with only 25°C.
HPS light heats up the plants so even with 25°C ambient you get the leaf temps where you want them. To grow at 25°C with LED's is simply not as efficient as to work with 30°C because of the lower metabolism.
I would rather use less light with higher ambient temps as the opposide but to reach canopy temps of 28-30°C alone with my LED light I need at least 700-800μMol/s/m² across the canopy(30-35w/sft.). Only in the summer month I need less.
I can say it again and again ..
You want the LST or better the temperature of the whole plant as close to 30°C as possible to allow her to make use of all the light. A plant getting 1500μMol/s ppfd with 20°C can simply not use all the light cuz their metabolism is just running too low. You would see slow growth and probably bleaching or other signs of saturation when you do is nevertheless.

I agree, looking at that graph I can see where its demonstrating lower photosynthetic rates with lower temps. This is also evidenced in the graph I posted..


This previously posted graph may even contradict, my contradiction lol, look at the water usage effeciency. Seems to go down as transpiration increases.

The whole thing where im getting stuck, and could possibly be due to my irregular experience between HPS and LED (why I want to plot some data), is it seems that HPS has more natural RH noticed in the grow area than LED. This would seem to contradict that LEDs are causing more transpiration than HPS. But I'm definitely no expert either and just trying to further the discovery.

 

[ChiefRunningPhist]

No worries. If you had hydrogen and oxygen in your grow space you could have quite the explosion, think space shuttle Challenger accident.

Well we know that O2 exists in our atmosphere, not sure the percent of H2, or if it exists naturally though. I figured it would depend on the concentration and figured it wouldnt have an effect, but idk, seems like you might know more.

 

[nobighurry]

I used T5s for seedlings & veg forever but I decided to give 3 288qb LEDs a try on some clones and wow! They blew up I was shocked at the differance from the previous clones (same mother) Under the T5s... I run a couple hps in the flower room but the girls in there were slow so I started flowering with the LEDs week 3 I started getting issues added epsom salt and worm castings things improved, I moved them under the hps and within 4 days they were 100% better, 68deg F RH 65%... So I am very interested in this thread, I would like to try LEDs for flowering to save on the power bill

 

[ChiefRunningPhist]

Just throwing out some more possible ideas.

http://www1.lsbu.ac.uk/water/magnetic_electric_effects.html

Idk what I think anymore lol seems that increasing RH is helping when it comes to LED, so I'm not advocating against such things, just trying to understand why it works as I'm having hard time with the over transpiration reason stated. It could very well be true, I'm just looking for the why. Maybe we are applying a fix, but are wrong about what it's fixing? Or maybe we're right and I'm just blowing up someone's thread lol

 

[Randomblame]

Well we know that O2 exists in our atmosphere, not sure the percent of H2, or if it exists naturally though. I figured it would depend on the concentration and figured it wouldnt have an effect, but idk, seems like you might know more.

I've found out when you add lets say 1000-1500ppm CO2 the water usage is also reduced by 30 to up to 50% cuz plants need to breath less with high CO2 concentration. So it adds another variable. Oxygene content is pretty low(O²) and hydrogene(H) is less than 0,05% or so. It needs electricity to splitt water into H and O and natural H will probably react with O or other elements..


Wait, I will ask google for some useful pics..
Found the "air wiki"..

 

[Randomblame]

Just throwing out some more possible ideas.
View attachment 4303455
http://www1.lsbu.ac.uk/water/magnetic_electric_effects.html

Idk what I think anymore lol seems that increasing RH is helping when it comes to LED, so I'm not advocating against such things, just trying to understand why it works as I'm having hard time with the over transpiration reason stated. It could very well be true, I'm just looking for the why. Maybe we are applying a fix, but are wrong about what it's fixing? Or maybe we're right and I'm just blowing up someone's thread lol

Instead searching for other reasons why you should at 1st have a closer look on VPD and every single aspect of it. Here is a good guide providing lots of information.. Not especially for cannabis but that plays no role. The princip is the same for all plants only the optimal ranges( for germ, veg & flower) differ a bit because of different species.

https://getpulse.co/blog/vpd

 

[Capn-Crunch]

This is day 2 of bringing my temps down a bit and getting my humidity up to 65% and I'm freaking amazed at the difference
in the plants in my LED tents!!!!!!
I'm sold. It works, and works well.

 

[ChiefRunningPhist]

Instead searching for other reasons why you should at 1st have a closer look on VPD and every single aspect of it. Here is a good guide providing lots of information.. Not especially for cannabis but that plays no role. The princip is the same for all plants only the optimal ranges( for germ, veg & flower) differ a bit because of different species.

https://getpulse.co/blog/vpd

Ok thanks for the discussion.

 

[Special Kdog]

All this sounds like a bunch of gibberish. Have you checked your CO2 levels or tried supplementing them?

 

[Capn-Crunch]

All this sounds like a bunch of gibberish. Have you checked your CO2 levels or tried supplementing them?

Not gibberish at all

 

[nachooo]

Have to add my own experience… Got the same problems when started to use leds lot of years ago...my local RH is very low so this agravated the issue...low rh and cold winters…
I was mad looking for a cure...what happened to my plants…? they have some strange simptoms...like bleaching but with not high intensity...like magnesium deficiencies...purple stems etc.... First I believe it was ph related… then a nutrients issue ..then that my tap wáter was bad… until one day I understand what @Randomblame have well and nice explained. I Just put the temps up and the humidity controlled by a sonoff with an humidifier that raise the it…. and the vpd was ok again .Also important to notice that if you can not raise humidity when high VPD ..you can low your nutes…
Since the VPD is being controlled...plants are without nutrient issues (I use megacrop), I also learnt to use high PPFD with high temps and high humidity to grow plants bigger and faster…
Think the info in this thread should be printed and be placed in the box where every led growing lamp is sold….Thanks Randomblame for write it in a compresive way.

 

[Randomblame]

Have to add my own experience… Got the same problems when started to use leds lot of years ago...my local RH is very low so this agravated the issue...low rh and cold winters…
I was mad looking for a cure...what happened to my plants…? they have some strange simptoms...like bleaching but with not high intensity...like magnesium deficiencies...purple stems etc.... First I believe it was ph related… then a nutrients issue ..then that my tap wáter was bad… until one day I understand what @Randomblame have well and nice explained. I Just put the temps up and the humidity controlled by a sonoff with an humidifier that raise the it…. and the vpd was ok again .Also important to notice that if you can not raise humidity when high VPD ..you can low your nutes…
Since the VPD is being controlled...plants are without nutrient issues (I use megacrop), I also learnt to use high PPFD with high temps and high humidity to grow plants bigger and faster…
Think the info in this thread should be printed and be placed in the box where every led growing lamp is sold….Thanks Randomblame for write it in a compresive way.

Bahahah, I have exactly the same odyseé behind me, lol!
I've even thrown away my cheap 4x 2' tent believing it's releasing PVC plasticizers, lol!
Had a pretty hard time to learn that stuff and I only wish someone would have told me earlier how important the VPD is.
It is not for nothing called "the hidden force acting on plants".

 

[Keesje]

@Randomblame

Would adding some infrared leds to 'normal white' leds in your tent solve the problem?
Or is this an oversimplified thought?

I copied all your remarks and put them in a seperate document, so I can read it again and again. I'am a pretty sure that managing ones VPD would be the sollution to many problems that people now try to solve with buying more useless additives or changing the lay-out of their growroom or whatever.

 

[charsi420]

Been using Calmag @ 5ml/g during veg and currently in week 3 fl at 2.5ml/g. Problem is that my bottle of Calmag is about to finish and the new one is en route but delayed. I have enough for another 3 days (2G per day) and the bottle in transit will take a week to get here.

What's would be the best approach to use the remaining 15ml? I think my cation exchange is already messed up as I'd reduced the dosage to 2.5ml/g for a week during veg after observing some minor clawing. Run-off since then has always been lower than what I put in, even after restoring it to 5ml/g.

 

[nachooo]

Bahahah, I have exactly the same odyseé behind me, lol!
I've even thrown away my cheap 4x 2' tent believing it's releasing PVC plasticizers, lol!
Had a pretty hard time to learn that stuff and I only wish someone would have told me earlier how important the VPD is.
It is not for nothing called "the hidden force acting on plants".

I have 12 of 3 watts 730 nm leds bought about 6 years ago or more ..think they were epistar...cheap ones.. also I have two 50 watts infrared ceramic opaque black lamps for terrarium..that ones that do not emit light and have a round flat shape.

My grow space is 1 square meter.. a 3x3 more or less.. and I usually have about 1000 ppfd in flower and about 300 ppfd in veg.. also I use 20 watts of UVA from veg to end and a Little UVB at the end.. White leds are about 3500 K 80 CRI. Some CO2 with yeast and sugar also.
I use the far red also as EOD, but only after two weeks of flower

Would you add some watts of far red in veg and flower to the main spectrum all over the day, just to improve transpiration efficiency?
I Will control vpd also of course..just trying to have all the bases covered…and try to mimic the sun
Also..
Would you add some watts of the infrared from the black ceramic lamps during the day to improve more that transpiration? I wonder if the radiant heat black lamps cause elogantion like far reds...as they do not emit any light..is not clear to me

Or should I try 850 nm leds instead? .
.
I understand that I should mantain a red/far red ratio to avoid shade response, but I think that with 10 watts in veg and 20 watts in flower wont be a problema..also this leds dont seem very efficient..

Thanks for your time