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LED feed demands

chilliwilli

Waterboy
Veteran
Yeah n is quiet low, made the mix a year ago. Veg was already slow and i used 5ml canna bio vega once and a cup of biovin(2.4-0.7-2.2) and got better grow.

My rh% is also low more 40-45%. I have a dehumidifier in front of the bloomroom set at 55% that is running but as soon as the air enters it drops.
 
total stoner theory but what if Mg was less mobile at lower temps than high temps? It's a metal and metals get colder faster (and heat up faster) than other elements.

I was thinking about Borosilicate glass where the simple addition of boron slows the rate at which glass cools and expands (Coefficient of thermal expansion), thereby preventing fractures (Thermal shock).

Maybe singular elements have a temperature range, like Mg, and effect mobility in plants? VPD rates are a ratio so maybe magnesium has a ratio of VPD and PAR energy?
 

Cactus Wes

Active member
Interesting.
Lately, instead of pulling out the measuring tape and making sure the LED light is at an exact distance from the canopy; I have been keeping the light back and letting the plant(s) grow into the optimal zone. I like the results so far. I see elongated kolas instead of golf balls in one controlled observation. Which is amounting to more weight in this one instance.
(Light was too close.lol)
*If you suspect your light is causing a deficiency try raising your light a few inches.
This thread is interesting.
 

TPFTFW

Active member
Veteran
your pics in that other thread where you say your plants are drying, looks like what plants do when getting too much light under LED’s.
back off the light, and you’ll see a huge difference.

I was keeping my 640w literally 4 feet away and @ 50%
only bump it up as they’ll allow, try not to start off too heavy rather too light.

1FF9C145-06D9-418D-B9FB-A0FDBE618772.jpeg


.
 

GoatCheese

Active member
Veteran
your pics in that other thread where you say your plants are drying, looks like what plants do when getting too much light under LED’s.
back off the light, and you’ll see a huge difference.

I was keeping my 640w literally 4 feet away and @ 50%
only bump it up as they’ll allow, try not to start off too heavy rather too light.



.

Yes, this.. Most problems with white leds come from the lights being too close to the plants/lights are using too many watts for that distance= the leaves get dehydrated, esp. when the air is too dry all ready (winter season).

Coco/hydro growing is more forgiving under white leds cause there is more water in the plant tissue than when the plants are growing in soil.The coco-plant in my bloom tent has no issues at all with my Cree cobs when the soil grown plants are just on the limit of getting leaf damage (dehydrated, going abit pale and dry)


The only thing I had to change with my nutrient feed when changing to leds/cobs was adding calmag and Epsom salts, nothing more. No extra nitrogen or anything ,my NPK nutrients are exactly the same as under a HPS.
 

jeezooz

Active member
New here but have done a bunch of successful grows since the 2020 covid lockdowns so will share my perspective. I only grow indoor in a 1m x 1m tent with cheap LED lights. Coco perlite mix in 5/7g fabric pots, H & G Cocos bottled nutrients plus banana peel tea from early flower, Cal-Mag as needed (meaning almost never). To adjust the spectrum I start the seedlings under a "cool" white COB unit drawings some 135W from the wall. At transition to flowering I add the 250W light with 3000K CXA2530 COBs and sometimes another 90W COB blurple. Indicas and hybrids are fed 1/2 strength nutes, sativas closer to 1/3 bottle dosage but I water more than most growers - the coco in the pots never dries out.

Where I am going with this is that I never had any nutes or lighting issues, other than when the pH of water drifted. Both white light units are adjusted for height using the Lux meter app on the phone and the blurple is positioned a bit lower than the seedling light (90W vs 135W). I aim at 10,000-20,000 lux for seedlings, 30,000 in veg and up to 50,000 - 70,000 late flower. My method may not work in soil or for HPS but a combination of large fabric pots with coco watered generously with low dosage nutes keeps the plants happy under LEDs. To give you an idea what this tek is capable of I recently pulled a pound dry from two plants in 99 days start to finish (1m x 1m tent).
 

f-e

Well-known member
Mentor
Veteran
Is it H&G that don't list their feeds properly? Making it hard to draw any conclusions over the Calcium and Magnesium needed. Which is where most peoples grow needs change
 

jeezooz

Active member
My main point is that heavy watering seems to go well with LED lighting and to be able to water more without overfeeding it makes sense to lower the dosage. Also, larger pots work better in this scenario. I buffer my coco with Cal-Mag before grows and sometimes supplement a bit later but others on this thread mentioned N and P deficiencies from LED and I never had these. The only nute lockout I had was caused by the pH issues and was fixed by flushing. There are many reports on the web from growers using very low nutes to power successful grows.
 

f-e

Well-known member
Mentor
Veteran
That's interesting. I have gone for more water, and it got worse. Then bigger pots, and it got worse. Drastically so. I'm about to go back to using my smallest and best draining coco dtw yet.

It's fairly established that you can't feed coco low or the buffer will be stripped. Calcium and Magnesium needs to be present in high amounts to take up the cec potential as the coco degrades, and feed the plants. If not, sodium and potassium can take the sites. Which is what we are constantly trying to flush away with coco. This is why I find the H&G's lack of labeling such a dead end. I'm happy it's working for you, but there is nothing else to learn, without knowing what you are feeding them.

I'm thinking the lack of water movement is leaving my pots sopping wet and the roots unable to get enough air. Leaving me with yields comparable to dwc or rockwool slabs.
 

jeezooz

Active member
If I start with an unbuffered brick or recycled coco I charge it with full strength Cal-Mag. If it is a brand new bagged pre-buffered mix I will still water with weak Cal-Mag before the seeds go in. I very rarely add remedial Cal-Mag or Epsom salts later.

You can check out the H & G ingredients - I chose them only because it is the most expensive range where I live. I start in final pots and water in small circles around the seedling first 3-4 weeks. When the plants fill the pot I start watering to runoff and continue this way until harvest.
 

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f-e

Well-known member
Mentor
Veteran
It's a shame to see a feed that supplies enough cal&mag, but doesn't list whats in it. I think they are the only brand that omits the information. To make it 4 weeks without runoff is something.

It's odd they would give the SG but not the breakdown of what's in there.
 

jeezooz

Active member
Watering without runoff first few weeks probably works in this tek because the nute level is so low - otherwise the salts would start accumulating in the pot.

BTW dubi recommends starting small and uppotting after the flip. This would not fit with my grow style which is ultimate simlicity. I aim to minimise the number of pots, saucers, bottles etc that I need to complete grows. Most containers I use have multiple functions - the seedling tray doubles as a trimming tray, empty jars hold spare coco mix, saucers with water are my low tech humidifiers etc.
 

JustGrowing420

Well-known member
Watering without runoff first few weeks probably works in this tek because the nute level is so low - otherwise the salts would start accumulating in the pot.

BTW dubi recommends starting small and uppotting after the flip. This would not fit with my grow style which is ultimate simlicity. I aim to minimise the number of pots, saucers, bottles etc that I need to complete grows. Most containers I use have multiple functions - the seedling tray doubles as a trimming tray, empty jars hold spare coco mix, saucers with water are my low tech humidifiers etc.

Regarding up-poting after the flip, it is recommended for pure sativas only, to control their stretch. Not as a general method for indicas/hybrids.
Taking information out of context could be dangerous.
 

f-e

Well-known member
Mentor
Veteran
Adding Humic Acid in bloom increased Calcium content of the bud leaves by almost 50% in a 2019 study.

Humic tends to cling to Calcium. It's use is often seen as a way of clearing things off the Calcium to make the things available. For us with freely moving Calcium (we pour it in) the Calcium itself becomes more mobile as the Humic helps it along.

I feel this gain in Calcium mobility, from adding Humic Acid, could be of use in LED farming.


Be aware that Humic speeds up THC degradation. The studies product saw over a third lower THC concentration. With relative gains in the degradation products of CBN & DHC
 

unnamedmike

Well-known member
Veteran
BTW dubi recommends starting small and uppotting after the flip. This would not fit with my grow style which is ultimate simlicity. I aim to minimise the number of pots, saucers, bottles etc that I need to complete grows.
You can fill the pots only part of their capacity, no re-potting is necessary.
 

abuldur

Member
I stoped using coco and started using hydro again.
No more problems .
Maxibloom ec 1.4 under 630 w osram leds temp 27c 70% humidity.
 

abuldur

Member
I am using generalhydro waterfarms with clay peebles and water strait from the tap ec:0.45 ph:7.5.
I then add 1 scoop of maxibloom or koolbloom whatever lies arround to bring my ec to 1.4.
 

f-e

Well-known member
Mentor
Veteran
Not the first person in clay pebbles, who's not increased calcium or magnesium.

I'm not sure mine want calcium anymore. I have a suspicion the pathways calcium takes were a bit restricted after generations under lights. A trait that took a while to fade. Now, I'm actually cutting back quite a bit of the extra calcium. Which has been beneficial in regards to Mg uptake. I'm way lower in Ca than I needed to be when I first went over to LED. Gene expression has certainly shifted. I'm just not able to gauge if HID caused a restriction when compared to sunlight. While LED would require easier passage than sunlight. I'm 100% sure they have been constantly adapting though, and that's been a couple of years going cut to cut.
 

abuldur

Member
Hi f-e ,
Just braught in a few plants which i veged outdoors under natural light.
I am going to flower them under 1060 w of osram leds at 27 c and 75 % humidity.
My goal here is to monitor the adaptation of these healthy outdoor veged plants to led lighting.
l am not going to change nutrition which is plagron bloom terra (basic dutch fert for dirt).
I will let you know..in a week or two…
 

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