LED's and cal/mag def = ONLY extra cal/mag needed or just up ppms due to more par levels?

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Dan_J

Active Member
Howdy folks ;)

With all the need for extra cal/mag under LED's i was just wondering if it's because of the spectrum of most LED's or are LED's just super efficient producing more par levels at closer canopy heights due to less heat thus the need to up the PPM's of the complete nutrients not just cal/mag?

thoughts?

cheers
 
I believe it is an effect of LIebig's Law of the Minimum. Adding higher quality light or more light increased the demand for Mg (and possibly Ca). Mg became the limiting factor.
 
Its better to think in totals than in concentrations: more efficient spectrum (possibly) but also that your led light doesnt create as much radiant heat, which means lower leaf temps, lower transpiration, drinking less. You have to dial it in between concentrations in the root zone and your environment. More of a weaker juice or less of a stronger juice.
But you can see only increase rootzone concentration up to a point, eventually youll create lock outs of no other nutrients.
So generally grow with a little hotter temps, especially in veg
 
Rocket Soul said:
Its better to think in totals than in concentrations: more efficient spectrum (possibly) but also that your led light doesnt create as much radiant heat, which means lower leaf temps, lower transpiration, drinking less. You have to dial it in between concentrations in the root zone and your environment. More of a weaker juice or less of a stronger juice.
But you can see only increase rootzone concentration up to a point, eventually youll create lock outs of no other nutrients.
So generally grow with a little hotter temps, especially in veg
Click to expand...
Agreed with rocket soul increase temps using led and say goodbye to mg deficiencies its tricky to do in winter but there are plenty of solutions
 
cat shit said:
Agreed with rocket soul increase temps using led and say goodbye to mg deficiencies its tricky to do in winter but there are plenty of solutions
Click to expand...
I use my t5 fixture and seedling mat for germination but also for extra heat while there young and the led is on a lower percentage works well in colder months and keeps humidity in an acceptable range i find oil heaters make things a bit dry even when iin the lung room.
 

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cat shit said:
Agreed with rocket soul increase temps using led and say goodbye to mg deficiencies its tricky to do in winter but there are plenty of solutions
Click to expand...
One of those solutions is hanging a few low watt incandescant lightbulbs, but you really have to be carefull and balance it wih the rest of the lighting: they can cause a lot of stretch.
@Moflow is an inspiration when it comes to growing with leds in the cold, i think he quote insulating his veg space with foamboard and a little epson, magsulfate in the substrate.
 
Rocket Soul said:
One of those solutions is hanging a few low watt incandescant lightbulbs, but you really have to be carefull and balance it wih the rest of the lighting: they can cause a lot of stretch.
@Moflow is an inspiration when it comes to growing with leds in the cold, i think he quote insulating his veg space with foamboard and a little epson, magsulfate in the substrate.
Click to expand...
Thats sounds very interesting. and the t5 is just for heat as the led is feeding the plants its kind of a waste of resources and power but as long as they are warm the outcome is usually worth it.
 
Dan_J said:
Howdy folks ;)

With all the need for extra cal/mag under LED's i was just wondering if it's because of the spectrum of most LED's or are LED's just super efficient producing more par levels at closer canopy heights due to less heat thus the need to up the PPM's of the complete nutrients not just cal/mag?

thoughts?

cheers
Click to expand...
Yes, id say up total ppms a bit aswell.
 
appreciate the engagement folks.

will trial and see, first incrementally up my ppm till signs are showing burn and see how that goes, then extra cal/mag if i see the need.
reason for that method is just to rule out and see what helps .

thanks
 
Dan_J said:
appreciate the engagement folks.

will trial and see, first incrementally up my ppm till signs are showing burn and see how that goes, then extra cal/mag if i see the need.
reason for that method is just to rule out and see what helps .

thanks
Click to expand...
Unless your plant has an insufficient level of nutrients, I would recommend against increasing EC simply because your PPFD goes up.

More nutrient ≠ increased growth. In terms of nutrients, growth is maximized by giving a plant sufficient levels of chemicals in the fertilizer.

If light levels increase, photosynthesis will tend to increase and that results in increased glucose. The increased glucose levels allow the plant to respire more and plants grow faster. With faster grow rates, increased mass, and increased surface area, water demand is increased which in turn brings in more nutrients.

Adding nutrients will make the grower feel better but, from the perspective of the plant, increasing EC + increasing light levels will, overall, be of, at best no value to the plant and may move the plant into the toxicity range.


Nutrient Sufficiency.png
 
Dan_J said:
appreciate the engagement folks.

will trial and see, first incrementally up my ppm till signs are showing burn and see how that goes, then extra cal/mag if i see the need.
reason for that method is just to rule out and see what helps .

thanks
Click to expand...
What type of medium are you in? We balance ec in with whatever EC out we get. First water one plant and measure; and then adapt the feed and water it again if needs be. Take note on your ec out and figure out what works best for you. We saw good results from increasing EC during mid flower (coco dtw) maintaining EC out lower than 3 but pretty full on. But balancing it out to get a low ec out in the end of flower gets a bit challenging.
 
Rocket Soul said:
Its better to think in totals than in concentrations: more efficient spectrum (possibly) but also that your led light doesnt create as much radiant heat, which means lower leaf temps, lower transpiration, drinking less. You have to dial it in between concentrations in the root zone and your environment. More of a weaker juice or less of a stronger juice.
But you can see only increase rootzone concentration up to a point, eventually youll create lock outs of no other nutrients.
So generally grow with a little hotter temps, especially in veg
Click to expand...

Yeah, exactly like that.
I'd just add that it is the calcium intake especially that increases with increase of transpiration.

And LED's usually decrease the temps, often changing the VPD while at it.
So just make sure you have high enough temps for good growth and your VPD is still within sufficient range.

The LED's needing more cal/mag is more of a myth.
Calcium is the one affected most with transpiration.
After that it's just not having too much of any of the K,Ca,Mg, but proper ratios.
Too much of any of the 3 and others uptake suffers.
 
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