LED feed demands

[THC123]

Try adding a cheap blurple !!! That really helped with these problems you are describing. They should look better within 5-7 days.

I have 22-25 degrees celsius and constant 65-70% RH in the room where i have the sf so I doubt raising RH will be a solution. I still have these issues what he is describing.

 

[MICrazy]

Your vpd is off.. raising Temps will just make it worse. Instead, keep it 78 but raise your humidity to 65%. Check out a vpd chart..
imho.
Also that's a pretty big dose of dolomitic lime... gotta wonder where your ph ended up - maybe you are seeing iron def?

I was running 65 for a while, just let things settle where they would be without humidification to see, and 55 is where it ended up. With a tiny bit of active ventilation -- I'm constantly pumping humidity to maintain 65... I could go back to selective ventilation based on temp/humid. Not sure.


2T/gallon seems pretty common for Dolomite. It's only been a month, maybe it's still cycling. Haven't tested ph this batch yet, but at the end of last run it was 5.8-6.2. Peat based starting mix, but not replacing it on re-amending. Just adding a little coco, rice hulls, little perlite, compost, castings, etc. It's still fluffy.

 

[MICrazy]

Try adding a cheap blurple !!! That really helped with these problems you are describing. They should look better within 5-7 days.

I have 22-25 degrees celsius and constant 65-70% RH in the room where i have the sf so I doubt raising RH will be a solution. I still have these issues what he is describing.

I'm running 6 lights in my tent right now. 3 HLG quantums, 1 atrium, and 2 QB96 Elites. So I have a bit of red already.


I've considered a Flouro IR, but most of my limited research says +9 degrees with LEDs get leaf temps up to HID levels.


I cam bump temps and RH just by doing on-demand ventilation. Might try that first, but I'd have to redo my drying tent. Right now it vents into my grow tent, everything is negative pressure so smell is contained.

 

[hyposomniac]

I was running 65 for a while, just let things settle where they would be without humidification to see, and 55 is where it ended up. With a tiny bit of active ventilation -- I'm constantly pumping humidity to maintain 65... I could go back to selective ventilation based on temp/humid. Not sure.


2T/gallon seems pretty common for Dolomite. It's only been a month, maybe it's still cycling. Haven't tested ph this batch yet, but at the end of last run it was 5.8-6.2. Peat based starting mix, but not replacing it on re-amending. Just adding a little coco, rice hulls, little perlite, compost, castings, etc. It's still fluffy.

If you haven't checked it out yet, there's a video by bruce bugbee called maximizing cannabis yields.. He uses 40g dolomite per ft3.. a cup is almost 10x that. His mix isn't cutting edge but it's peat based, and i reckon he has the liming aspect well calculated and measured.
It couldn't hurt to do a slurry test.
I hope you take this as friendly chatter and not. criticism

 

[MICrazy]

I hope you take this as friendly chatter and not. criticism

No worries, I'm not that sensitive


I have a soil probe and a digital probe, but soil ph tests feel a bit like voodoo, lol.



The seedlings look perfect, the clover looks perfect (although next run I'm gonna try without -- since I don't notill it's a bit of a pain in the ass. I was hoping it would jumpstart the biology/myco but it gets out of control fast)

 

[MICrazy]

If you haven't checked it out yet, there's a video by bruce bugbee called maximizing cannabis yields.. He uses 40g dolomite per ft3.. a cup is almost 10x that.

Plus, I use well water that has a fair amount of calcium in it. So the 10% Mg in dolomite I was thinking would help with the C:Mg ratio. I'm not opposed to a epsom drench, next run I might try that.



Gonna fire up a couple more this weekend, last of the perpetual cycle. I have another batch of reamend that's a bit hotter, or I might just do a run in straight FFOF to see as a comparison.


The 3 that I'm referencing in this thread got fed last weekend (30 day mark) and for science and all, I fed them all slightly different to see if nutrients affected anything. One I fed a little alfalfa+kelp+compost. Another got bloom mix+kelp+compost. The last got just kelp+compost. Hasn't been long enough to notice any difference yet. Next watering I'm going to hit them with some microbes, although at current stage it's > a week inbetween waterings in 7g pots.

 

[Corn Planter]

Plus, I use well water that has a fair amount of calcium in it. So the 10% Mg in dolomite I was thinking would help with the C:Mg ratio. I'm not opposed to a epsom drench, next run I might try that.



Gonna fire up a couple more this weekend, last of the perpetual cycle. I have another batch of reamend that's a bit hotter, or I might just do a run in straight FFOF to see as a comparison.


The 3 that I'm referencing in this thread got fed last weekend (30 day mark) and for science and all, I fed them all slightly different to see if nutrients affected anything. One I fed a little alfalfa+kelp+compost. Another got bloom mix+kelp+compost. The last got just kelp+compost. Hasn't been long enough to notice any difference yet. Next watering I'm going to hit them with some microbes, although at current stage it's > a week inbetween waterings in 7g pots.

Good for you on the well water. Well water seems to contain a lot of elements that help feed. Some say never use well water but never had an issue. Actually I have problems when using store bought or clean sourced. I have a nasty well full of iron, sulfur, but plants seem to love it. I use epsom salt lightly on soil surface and water in for some plants that show fade in mid bloom, but too much or when not needed could cause issue?

 

[THC123]

Your vpd is off.. raising Temps will just make it worse. Instead, keep it 78 but raise your humidity to 65%. Check out a vpd chart..
imho.
Also that's a pretty big dose of dolomitic lime... gotta wonder where your ph ended up - maybe you are seeing iron def?

Why dot you buy a cheap IR thermometer? This way you can meaure LST.

 

[voidpainter]

Room temps don’t tell you much. I measured 72 on leaves in a 85F room with LED.

To raise leaf temps 9 degrees costs more than an ounce of epsom.

I guess that works since ppl have had success just by raising the lst.

IR, UV or whatever costs more than an ounce of epsom.

I guess that works too.

But ...

Epsom foliar did the trick over here. Less than a $. Applied a couple of times with a heavy dose, 6g / L. Dope green since the treatment 3 weeks ago. 6g might look a lot but epsom is magnesium sulfate heptahydrate, thats like half water in there, maybe even more. EC was measured at 1.6, dont really care about that, was measured for fun. pHed to ~6.5 with citric acid before application and added 0,2g of yucca powder as a surfactant. Did the trick, maybe half of the recipe is bro science but it worked.

Custom soil mix, water only from beginning with occasional kelp teas. LST 72F, room 82-85F, rH 65-70%, ~650 PPFD at the moment.

I tested CalMag+ on one plant, foliar and drench. No difference. Epsom applied plants surpased that. It gave me the N claw since CalMag products are usually based on Ca and Mg nitrates. I might use it still if I ever encounter Fe, Zn and Mn issues since this product includes them with the Ca and Mg.

 

[MICrazy]

Good for you on the well water. Well water seems to contain a lot of elements that help feed. Some say never use well water but never had an issue. Actually I have problems when using store bought or clean sourced. I have a nasty well full of iron, sulfur, but plants seem to love it. I use epsom salt lightly on soil surface and water in for some plants that show fade in mid bloom, but too much or when not needed could cause issue?

Mine has a fair amount of iron too, it'll drop out if I let it sit even after filtering. Sulfur too. I've thought about top dressing some epsom.

 

[MICrazy]

Room temps don’t tell you much. I measured 72 on leaves in a 85F room with LED.

Temp gun is on the list, but if I was running 78, cranking it up a little will at least move the needle.


Cranked up the existing LEDs a little, added another one, and redid the ventilation to operate on triggers/limits now instead of always on. Got 5 degrees and some extra RF so now I'm at 84F, 65%


Not sure my par, I just eliminated all the ratchets and affixed the LEDs to the top bars. I'm in major simplification mode.



I did foliarx3 at 1t/gallon+yucca. I think it helped. Top growth isn't striped, old stuff looks about the same. Getting later in flower for a couple so spraying is probably done. I still have calmag but... nah. Zero signs of calcium def. Next run I might try top dressing some epsom on transplant.

 

[THC123]

Room temps don’t tell you much. I measured 72 on leaves in a 85F room with LED.

To raise leaf temps 9 degrees costs more than an ounce of epsom.

I guess that works since ppl have had success just by raising the lst.

IR, UV or whatever costs more than an ounce of epsom.

I guess that works too.

But ...

Epsom foliar did the trick over here. Less than a $. Applied a couple of times with a heavy dose, 6g / L. Dope green since the treatment 3 weeks ago. 6g might look a lot but epsom is magnesium sulfate heptahydrate, thats like half water in there, maybe even more. EC was measured at 1.6, dont really care about that, was measured for fun. pHed to ~6.5 with citric acid before application and added 0,2g of yucca powder as a surfactant. Did the trick, maybe half of the recipe is bro science but it worked.

Custom soil mix, water only from beginning with occasional kelp teas. LST 72F, room 82-85F, rH 65-70%, ~650 PPFD at the moment.

I tested CalMag+ on one plant, foliar and drench. No difference. Epsom applied plants surpased that. It gave me the N claw since CalMag products are usually based on Ca and Mg nitrates. I might use it still if I ever encounter Fe, Zn and Mn issues since this product includes them with the Ca and Mg.

Here calmag plus helps better than epsom salts, epsom salts has no effect here....I used all the epsom salts I had, it is finished now. I gave it with watering and foliar but to no avail....strange huh

I havent tried 6g/liter though, might try that.

 

[voidpainter]

Haven’t noticed much myself until I hit them with 6g / L.

2g / L worked when the cuts were like 2 weeks old. But when the total leaf mass got huge it didn’t cut it anymore. Tried 3g / L and nothing. 6g / L made an overnight difference.

I would be careful here tho if anybody tries this. the mix used is loaded with Ca and almost no Mg. Might cause Ca deficiencies for other types of mixes / styles. I’m not sure, just a warning.

 

[Shmavis]

Seedlings under HLG 65 V2 @ 4000K:

Seedlings under HLG 65 V2 @ 4000K:

Well over two feet from the light; PPFD less than 150.

One week later:

Sown directly into my soil mix instead of a seed starter mix. Should have more than enough available nutrition... seedlings never react this way under T5 or CFL... dusted off my adjust-a-wing for the fall season...

 

[hyposomniac]

Why dot you buy a cheap IR thermometer? This way you can meaure LST.

I have one in fact.. Use it for cooking more often than gardening .. but I'm not the one having problems (not at the moment at least, ha)
So is there a way of using leaf temp to make practical adjustments?

I will say my leaf temp is pretty high.. just a couple degrees below room temp, 84 in an 86 room, directly ubder a qb.
That is after 10 hours of lights, dehuey on and a 90+ hot day.. Thats where my space peaks so far.. its usually just under 80 air temp. I just setup an exhaust that goes outside but havent switched to it yet.. flir paranoia
630cmh and 2 QBs running full tilt 150w each.

Only the biggest plant showed any yellowing.. bumped feed to 140ppm N/65ppm mg and she greened right up

 

[Joint Lock]

It seems that changing to LED, highlights deficiencies that we couldn't see before. That little thing, that would of made things better, but we couldn't see it before. However, this is just an opinion. Not shared by everybody.

The most common issues we see experienced growers having, before LED's, is Calcium and Magnesium. Due to softer water supplies combined with feeds that expected it to be harder. So it follows, that many of us were close to seeing such signs, but it's switching to a greater level of illumination that highlights it.

I think I'm seeing a few people switch to LED's and isolate that individual thing that was always holding them back, but never really showed itself. Then, rectifying the situation, by adding that thing to balance up their feed, and then increasing everything by perhaps 25%.


I'm here, as I'm interested in seeing a few peoples stories.

My story starts with me using flower food, from cuttings through to bud. But with Nitric acid in grow, and enough of it to actually raise the N level to that of a well known grow feed, Canna. I did this for some time. Then moved to LED's and saw a N deficiency. Which is really what you would expect. Now, I have to use grow food, and Nitric. The P acid won't do. On top of which, I have had to move my EC up from 13-14 to 16-17. Which is a huge shift in N usage. If I lower my feed, I still see the same signs I used to. N deficiency and a light chevron effect to my leaves. So I know I'm only feeding so high, to accommodate these.


So, I had to increase the N in my nutrient profile, then stick 20-25% more nutrient in.

What steps have other people taken, to ensure the correct feeding regime after switching to LED's ?

What u see is a faster metabolism from the plant which used mag and calcium a lil faster then normal lighting when using LED Thus due to intense beams of light made from lenses vs a reflector/hood

 

[User18]

Problem yellowish leaves

Problem yellowish leaves

Hello everyone, I would like to have advice if possible regarding this problem that I have encountered for a few days. Cultivation in 35 liters pot, lightmix soil plus perlite and coconut fiber, last fertilization on July 3rd, bio organic Vega of cane. In the lower part of the plant, the older leaves begin to turn yellow too frequently, and I am noticing that the petioles and stems near the leaves also begin to take on a darker color even in the upper part of the plant. I am attaching photos to better understand. Thank you

 

[MICrazy]

Wellp, after getting the chlorosis/chevron type effect on another plant -- and some other leaf yellowing, despite throwing epsom salts at it....


I finally got my hands on a Gain style ph probe. Measured the pot, 5.0. Measured the next batch of soil (same recycled base), 5.0. I figured the probe was bad. Stuck it in a bag of happy frog. 6.2. Ugh. My soil sucks. No wonder why throwing mag at it didn't do anything.


So now I have a little conundrum. 7 plants currently in this shitty soil. 2 are symptom free, 1 is a little lime but no chlorosis yet, and 4 are hurting. Going forward I am going to dump everything related to this soil and finally make my own.


My input water is 7.0-7.1. All of them had 2T/g dolomite during re-amending so not sure I want to add more. I'm going to experiment on one of them soon with a serious flush to see if that helps at all. Maybe buy/try some gypsum (although not sure I want more calcium, or how much would be flushed out). If I lose them (or cull them) I'd rather do it sooner.


More grower tax paid.

 

[THC123]

Well over two feet from the light; PPFD less than 150.

View Image View Image View Image View Image

One week later:

View Image

Sown directly into my soil mix instead of a seed starter mix. Should have more than enough available nutrition... seedlings never react this way under T5 or CFL... dusted off my adjust-a-wing for the fall season...

yeah that is my issue as well. It looks like there is too much light but the meter says it is ok. Only have this with qb,s. Under my blurple (or any other lightsource)i can start seedlings at 300 500 pond without issues....
Or there is something wrong with your lights or we are doing something horribly wrong.

 

[THC123]

What u see is a faster metabolism from the plant which used mag and calcium a lil faster then normal lighting when using LED Thus due to intense beams of light made from lenses vs a reflector/hood

Then this is only the case with these newer leds never had any issues under other leds. Must be the spectrum.