10 - Agrobar 720s over 6 - 4x8.5 ft rolling benches. F & D FTW

[Ca++]

I'm not sure how you would acidity the root zone, with F&D rockwool. Obviously there is some sort of rhisosphere, but any further from the root, and the zone is back n forth to the tank. You would see it.

Did you block K with high Ca? It looks like you got some stretch, and certainly some width, so P isn't outstandingly bad, if at all. I Just see lots of K signs. I presume it started with tip burn, then went up the sides. With symmetry that burn doesn't follow so well. There is rolling of the margin where the water retention mechanism has kicked it. So either it's water loss related burn, likely from K issues. Or you had low RH and other issues.

Very hard to say from here, when you were actually there. It just seems to scream K though, with the backing singers to support it. There is a feint notion of overfeed, but at 1.7 it really is feint. Though it depends what it's 1.7 of.

I hope my input prompts some useful thoughts. Though we might be better friends if I were a 'yes man' it's just not as motivating

Some chunk there regardless. I would of liked to see the net better filled though, and them obvious signs show there is a lot of room for improvement. Which might lead to a very impressive grow indeed. Can you collect all the leaves and spend a few £ on tissue analysis? If that's possible, you absolutely must.

 

[Crooked8]

I'm not sure how you would acidity the root zone, with F&D rockwool. Obviously there is some sort of rhisosphere, but any further from the root, and the zone is back n forth to the tank. You would see it.

Did you block K with high Ca? It looks like you got some stretch, and certainly some width, so P isn't outstandingly bad, if at all. I Just see lots of K signs. I presume it started with tip burn, then went up the sides. With symmetry that burn doesn't follow so well. There is rolling of the margin where the water retention mechanism has kicked it. So either it's water loss related burn, likely from K issues. Or you had low RH and other issues.

Very hard to say from here, when you were actually there. It just seems to scream K though, with the backing singers to support it. There is a feint notion of overfeed, but at 1.7 it really is feint. Though it depends what it's 1.7 of.

I hope my input prompts some useful thoughts. Though we might be better friends if I were a 'yes man' it's just not as motivating

Some chunk there regardless. I would of liked to see the net better filled though, and them obvious signs show there is a lot of room for improvement. Which might lead to a very impressive grow indeed. Can you collect all the leaves and spend a few £ on tissue analysis? If that's possible, you absolutely must.

I think they are both P and K deficient because we didnt add our PK booster until week 5 which was an oversight. Normally its applied lightly at week 3. We dont typically see this.

When plants are low on P, and seeking more, they acidify their own rhizosphere looking for it, they can drop their own PH by an entire 1.0. This almost always comes with micro toxicity unless remedied immediately. The reason i know this happened is because at week 4 we saw our ph in our res drop dramatically in 4/6 reservoirs. The others went down but only slightly. Normally we see almost no fluctuation and if anything the ph goes up slightly. It likely happened when i bumped the ppfd up to 90+% and hadent supplemented P-K.

Overall I agree with you regarding the K symptoms but the P ones are there too. VPD was pretty dialed the entire run so RH was not too low at any point especially in the first 3-4 weeks. We supplement cal mag but only at a low level and for weeks 1-5. A tissue test is a good call. If our next run shows these symptoms in week 5 ill send some of the most newly fully expanded leaves out. Thanks for your input, you are on point.

Overall still pumped to see these ripen, they are swol. Definitely room for improvement but my second run in any space has never been my best.

 

[Ca++]

Looks like a 10-12kg room. Tissue sampling is $30. Do you need a loan?

 

[Crooked8]

Looks like a 10-12kg room. Tissue sampling is $30. Do you need a loan?

No and theres even a spot i can drop them off at locally. Ill be doing it for sure this next run. Ill also be supplementing extra K starting week 3 because i do think thats the main issue. Thanks bud.

 

[Ca++]

Local drop off? I'm quite jealous. Here in the UK it's difficult. I can only use water sampling as a reflection of what they are taking out.
It would take a lot of leaves to sample every few days. There are clearly turning points in the crops direction, that can be targeted though. Perhaps building up a picture over a few runs. My most frequent testing is late transition. The 2 - 4 week period. Where we move from P to K. Sampling see's it before we do. Opening up the opportunity to add K just a little earlier. Not early enough to build to toxic levels (I use coco an soil a lot) but there in time, so as to not throttle proceedings.
For me, getting the P reduced is important. By week 4, the dryback is concentrating P way beyond what's fed to them. Numbers suggest they are not taking it, at a time many people are boosting it. Somewhat before the breadth of the flowers has formed. Bits of info like that (as others may not realise) are of great us in our attempts to steer a crop along. Rather than reactive gardening, which is by nature, trailing behind the plants needs.


I hope for the day when I can look at a deficiency and just say "I'm not guessing. Get a sample taken" Though for a home grower, getting a sample ball of leaves that fills your hands, might not be viable.


I look forward to your next set of pics. I'm still looking at the metal spiral duct and carbon on the floor with interest.

 

[Crooked8]

Local drop off? I'm quite jealous. Here in the UK it's difficult. I can only use water sampling as a reflection of what they are taking out.
It would take a lot of leaves to sample every few days. There are clearly turning points in the crops direction, that can be targeted though. Perhaps building up a picture over a few runs. My most frequent testing is late transition. The 2 - 4 week period. Where we move from P to K. Sampling see's it before we do. Opening up the opportunity to add K just a little earlier. Not early enough to build to toxic levels (I use coco an soil a lot) but there in time, so as to not throttle proceedings.
For me, getting the P reduced is important. By week 4, the dryback is concentrating P way beyond what's fed to them. Numbers suggest they are not taking it, at a time many people are boosting it. Somewhat before the breadth of the flowers has formed. Bits of info like that (as others may not realise) are of great us in our attempts to steer a crop along. Rather than reactive gardening, which is by nature, trailing behind the plants needs.


I hope for the day when I can look at a deficiency and just say "I'm not guessing. Get a sample taken" Though for a home grower, getting a sample ball of leaves that fills your hands, might not be viable.


I look forward to your next set of pics. I'm still looking at the metal spiral duct and carbon on the floor with interest.

People certainly are supplementing P in excess. Way too much to be honest. But the plants to mobilize it like crazy compared to most plant life. I agree with reducing P and increasing K around that time.

One thing to discuss, drybacks. When we do them and the results. According to the most recent advanced USU course, drying back may be dramatically reducing cannabinoid content. They experimented with drying back or water stressing plants to varying degrees. They saw results shockingly as high as 90% more cannabinoid content with the same cultivar in an environment with constantly saturated media. No drybacks. Its think drybacks early on assist in root development and are great up till week 3. At that point i dont think they are necessarily worth doing. I still obviously see lots of generative growth and im currently irrigating 2x a day.

Ill have some more pics up soon for sure. Let me know if there are any questions. I appreciate the sounding board and solid input.

 

[goingrey]

People certainly are supplementing P in excess. Way too much to be honest. But the plants to mobilize it like crazy compared to most plant life. I agree with reducing P and increasing K around that time.

One thing to discuss, drybacks. When we do them and the results. According to the most recent advanced USU course, drying back may be dramatically reducing cannabinoid content. They experimented with drying back or water stressing plants to varying degrees. They saw results shockingly as high as 90% more cannabinoid content with the same cultivar in an environment with constantly saturated media. No drybacks. Its think drybacks early on assist in root development and are great up till week 3. At that point i dont think they are necessarily worth doing. I still obviously see lots of generative growth and im currently irrigating 2x a day.

Ill have some more pics up soon for sure. Let me know if there are any questions. I appreciate the sounding board and solid input.

Do you have some kind of link for this or better yet their source?

No rush, gonna go water my plants.

 

[Crooked8]

Do you have some kind of link for this or better yet their source?

No rush, gonna go water my plants.

Unfortunately they remove all the modules when the class is over and they do all of their own research. Their stuff does end up published. Im not sure exactly how to find the info. But the tests were all thorough and done in chambers at the same ppfd, ec and co2 enrichment. Their testing is very precise.

 

[Ca++]

People certainly are supplementing P in excess. Way too much to be honest. But the plants to mobilize it like crazy compared to most plant life. I agree with reducing P and increasing K around that time.

One thing to discuss, drybacks. When we do them and the results. According to the most recent advanced USU course, drying back may be dramatically reducing cannabinoid content. They experimented with drying back or water stressing plants to varying degrees. They saw results shockingly as high as 90% more cannabinoid content with the same cultivar in an environment with constantly saturated media. No drybacks. Its think drybacks early on assist in root development and are great up till week 3. At that point i dont think they are necessarily worth doing. I still obviously see lots of generative growth and im currently irrigating 2x a day.

Ill have some more pics up soon for sure. Let me know if there are any questions. I appreciate the sounding board and solid input.

90% would be very drastic. It's actually scary. To think a nice 20% variety, would come out at 2% is a nightmare. Thankfully, they must of been really trying hard, to do that bad.

Plants certainly stall. Slowing down as they realise water is becoming scarce. It's surprising how long that last little bit can keep them alive, after seeing them fly through water when it's nice and fresh.

I'm automated in pots, which will often mean some get a bit too dry, while I'm waiting for others to also dry. Which in some cases, they simply don't as they are different strains or simply smaller. This means it's normal for me to have both plants that dry back heavily, or some that don't at all. I have taken a couple of days to reply, as I have been having a good visual inspection. I don't 'see' anything. Nor have I ever rolled one that seemed below the par of the previous one. I'm on it though.. as I do have the chems to do a decent analysis.

 

[Ca++]

This is good. An expert graph showing the P in the runoff, over the weeks. You can see this move away from P use after week 2 that I was speaking of. As stretch stops, P use drops.

It's bugbee's work on cannabis, so very relevant.
I had not seen the uptake later on so strongly, but do find they will eat almost anything by week 5, making over feeding in later weeks, very easy. Certainly the bud is accumulating some, in the hope of packing it into seeds. It's just storage though. It had no effect on the yield of anything useful.

At 25ppm, about 80% of the applied P gets taken
At 75ppm, 30% gets taken.

I have settled with 100ppm if I want lots of frame growth during stretch. Otherwise I have been better around 50ppm. In either case, I have just had too much as stretch finished and budding becomes the way.

In this study, bud tissue K was not effected, as they lifted the feeds K by 45ppm with the higher P runs. This leaves me scratching a bit, as P doesn't directly bother K. The bud tissue Ca went from 1.3% to 1.6% though, and the Mn gained about 40% with P's help. N lost 3%. Perhaps the P does reduce K, through assisting Ca.
In any case, they seemed to feel more K was a must, with higher P. Which could be good reason to get the P reduced, in an otherwise high EC environment.

It's about 3 weeks I start moving on the K. It's traditionally for flowers, and the plant has changed direction. I don't want to wait till 4 weeks like many PK boosts recommend. I get in a bit early. We could call it crop steering, or an attempt, at least. Obviously this is not the wisdom from our forefathers. They would talk of P forming flowers that K filled. I'm finding P is not particularly for buds though. It's better for me, to load it in early, then pull back. My K timing is work in progress. PK has always been a killer for me, and while I spent a lot of time trying to prove to myself it was the K, in later years P has perhaps become the problem ingredient. Rather than just not use PK, I'm being pulled towards K use, while recent studies tell me it's not even useful. I'm a little lost, but like you, I see signs that can only really be K.

Bugbee seems to run EC2.0 with drybacks to 6 or even 8. Only 30ppm of this is P. He also uses co2, so it might be comparable for you. The pH though... 6.5 in just about everything. He finds Fe deficiency to rare to worry about in cannabis. While low pH can give Mn tox. Which I actually have right now. Looks a bit like K, burning margins. It also knocks the colour out of some edges, turning them white.

 

[Crooked8]

This is good. An expert graph showing the P in the runoff, over the weeks. You can see this move away from P use after week 2 that I was speaking of. As stretch stops, P use drops.

It's bugbee's work on cannabis, so very relevant.
I had not seen the uptake later on so strongly, but do find they will eat almost anything by week 5, making over feeding in later weeks, very easy. Certainly the bud is accumulating some, in the hope of packing it into seeds. It's just storage though. It had no effect on the yield of anything useful.

At 25ppm, about 80% of the applied P gets taken
At 75ppm, 30% gets taken.

I have settled with 100ppm if I want lots of frame growth during stretch. Otherwise I have been better around 50ppm. In either case, I have just had too much as stretch finished and budding becomes the way.

In this study, bud tissue K was not effected, as they lifted the feeds K by 45ppm with the higher P runs. This leaves me scratching a bit, as P doesn't directly bother K. The bud tissue Ca went from 1.3% to 1.6% though, and the Mn gained about 40% with P's help. N lost 3%. Perhaps the P does reduce K, through assisting Ca.
In any case, they seemed to feel more K was a must, with higher P. Which could be good reason to get the P reduced, in an otherwise high EC environment.

It's about 3 weeks I start moving on the K. It's traditionally for flowers, and the plant has changed direction. I don't want to wait till 4 weeks like many PK boosts recommend. I get in a bit early. We could call it crop steering, or an attempt, at least. Obviously this is not the wisdom from our forefathers. They would talk of P forming flowers that K filled. I'm finding P is not particularly for buds though. It's better for me, to load it in early, then pull back. My K timing is work in progress. PK has always been a killer for me, and while I spent a lot of time trying to prove to myself it was the K, in later years P has perhaps become the problem ingredient. Rather than just not use PK, I'm being pulled towards K use, while recent studies tell me it's not even useful. I'm a little lost, but like you, I see signs that can only really be K.

Bugbee seems to run EC2.0 with drybacks to 6 or even 8. Only 30ppm of this is P. He also uses co2, so it might be comparable for you. The pH though... 6.5 in just about everything. He finds Fe deficiency to rare to worry about in cannabis. While low pH can give Mn tox. Which I actually have right now. Looks a bit like K, burning margins. It also knocks the colour out of some edges, turning them white.

This is very good info! Where did you see bugbee at 2.0 ec? Their jacks formula is typically fed at 1.4 according to the course. Weve had our best results and yield when we stay in that range. Last run i hit 1.8-2.0 in some res and they didnt do as well as before in other spaces. It was our first run in the room though and a lot has been amended since then. My base is house and garden though so my 1.4 ec has a different composition than their jacks formula. So many variables man. My necrotic edges on the leaves this run really piss me off but im really happy with the bud structure and what appears to be a very terpy, sticky product. If i was lacking K it must have only been early on because most of the buds are extremely huge and very dense. I dont think yield will be an issue this round. Im anticipating a very nice yield and quality. Id love to see your work my friend!

 

[Ca++]

The EC2... 6..even 8 comment was in a youtube. Some guy interviewed him in an Athena hat, that looked like a rabbit between the headlights. Part#21 iirc.
Was 1.4 perhaps without co2?
I didn't realise it was a course of theirs. Did it cost much?

 

[Crooked8]

The room is crushing, super happy. Ca++ is on the money about K deficiency. Ill be supplementing it starting on week 3 next cycle. But, didnt seem to hurt the yield much. These buds are beyond huge and they are healthy and iced out like crazy. Terps will be off the charts. Cant wait to see the yield. Still seeing bright white roots in every slab. As someone who suffered from some pythium issues in DWC in the past, its a sight for sore eyes. Glad i went back to ebb and flow. Its SO simple!

 

[Crooked8]

Veg space, ready to head into flower in about a week-10 days. This is the first cycle where they are all actually a manageable size before going in. Ive had to wrestle overgrown monsters into place both prior rounds. Really excited for this coming harvest but im pretty sure this next one will be even more epic.

 

[Ca++]

They look nice man
Through a little experimentation, I have also confirmed it's K. I dropped from 280ppm to 240ppm and got the same signs in a couple of days. I had also moved the pH from 5.8 to 6.2 for nearly a week, which wouldn't help K. No change in Ca or Mg, which pretty much seals it. Bugbee likes 242ppm for the perfect tank/plant balance, but I need a bit more it seems. Perhaps as the peat has it's cec playing with things. I'm not sure where you were at, but the numbers may help.

Some good pics. I can almost smell some of it

 

[Crooked8]

They look nice man
Through a little experimentation, I have also confirmed it's K. I dropped from 280ppm to 240ppm and got the same signs in a couple of days. I had also moved the pH from 5.8 to 6.2 for nearly a week, which wouldn't help K. No change in Ca or Mg, which pretty much seals it. Bugbee likes 242ppm for the perfect tank/plant balance, but I need a bit more it seems. Perhaps as the peat has it's cec playing with things. I'm not sure where you were at, but the numbers may help.

Some good pics. I can almost smell some of it

It sure is stinky in there. Im super looking forward to seeing if I can keep them happier through the entire cycle next round. Again, very appreciative of your input, i think you are spot on. I do think these lights and overall cardinal parameters being at a high rate is a big factor. Ive not even supplemented P or K before through an entire cycle and not seen the chlorotic and necrotic edges like that. I mean maybe a little here and there but the whole room got it. To add to this, the buds furthest to the outer perimeter had the least signs of it, shocker, also where the ppfd was the lowest. Just another episode of “learning how to handle crazy LEDs”. I love this shit.

 

[Mars Hydro Led]

Great setup, the rooms are well organized and clean. Is this the first planting after your room is built?

 

[Crooked8]

Great setup, the rooms are well organized and clean. Is this the first planting after your room is built?

This was round 2

 

[CannaT]

I dont ever use great amount of P...only if you plan to make seeds. I learned over the years while growing hydro that seeded crop need P...
In all other situations K is the way to go.
P can be toxic to plants very easy and I dont want to fight with that beast it can easy ruined your crop.

In fact I use in Hydro setups HNO₃ and KOH as PH up and PH down...cuz plant eat them always.

By looking to your plants I will say you need faster metabolism.Bit more benefical stress.
I think its to cold for them again.
I will give them higher root or room temp and maybe more wind.

But as Ca+ say its hard to say what it is..cuz never been there.
Anyway good grown plants.

 

[Crooked8]

I dont ever use great amount of P...only if you plan to make seeds. I learned over the years while growing hydro that seeded crop need P...
In all other situations K is the way to go.
P can be toxic to plants very easy and I dont want to fight with that beast it can easy ruined your crop.

In fact I use in Hydro setups HNO₃ and KOH as PH up and PH down...cuz plant eat them always.

By looking to your plants I will say you need faster metabolism.Bit more benefical stress.
I think its to cold for them again.
I will give them higher root or room temp and maybe more wind.

But as Ca+ say its hard to say what it is..cuz never been there.
Anyway good grown plants.

Thanks for your input! I dont necessarily think its a temp issue, ive kept vpd in check the whole time. They also grew quite rapidly and drank an average amount. Not too fast or slow. Ive been trying to dial back the feed and i think we just took that notion a tad too far. I have a K supplement for this next round. Well see what it does for us. We use an anemometer to make sure wind speed is in check so we can rule that out. Overall i just think we waited too long to add hydroplex to our feed. When weve run it earlier in the past we didnt see the K def. If you look at some of my past grows you can see they are typically very healthy. Anyway, live and learn! Thanks