Question regarding Ca uptake in early flower and VPD

[Three Berries]

Seeing as my issue is 100% new growth it needs to be done in a timely manner depending on how fast it's growing. I just up potted the two small ones and they are being lazy as far as growth.

I foliar sprayed once a week but that would not be enough as it needs a daily fix.

Pretty sure this is an issue with my tomatoes too as I've been slacking on the limestone. Should have a banner year outside with my 50# of calcium nitrate.

 

[ButterflyEffect]

Seeing as my issue is 100% new growth it needs to be done in a timely manner depending on how fast it's growing. I just up potted the two small ones and they are being lazy as far as growth.

I foliar sprayed once a week but that would not be enough as it needs a daily fix.

Pretty sure this is an issue with my tomatoes too as I've been slacking on the limestone. Should have a banner year outside with my 50# of calcium nitrate.

What medium are you in again?

I've been struggling with random deficiencies in veg a lot lately. Although, I think it was due to it being too hot in the room with too low humidity. I raised it and they're responding well now so maybe that was the issue all along. As always I'll be keeping a close eye on things.

 

[Three Berries]

I use Happy Frog with some added perlite. The flower plants did not need any today but the veg plants did.

 

[ButterflyEffect]

I use Happy Frog with some added perlite. The flower plants did not need any today but the veg plants did.

It won't be easy to draw parallels between my setup and yours with respect to deficiencies. I'm in almost straight perlite now. Flower plants are fed 3 times a cycle. Still, I think the CaCl will be a beneficial foliar to have in the arsenal.

 

[Three Berries]

It won't be easy to draw parallels between my setup and yours with respect to deficiencies. I'm in almost straight perlite now. Flower plants are fed 3 times a cycle. Still, I think the CaCl will be a beneficial foliar to have in the arsenal.

Never grown in anything else. But the foliar feeding has not done much for me as it cannot be done daily, or I have not done it daily.

I suppose I could try spraying just the new growth if emerging yellow.

 

[ButterflyEffect]

Never grown in anything else. But the foliar feeding has not done much for me as it cannot be done daily, or I have not done it daily.

I suppose I could try spraying just the new growth if emerging yellow.

I imagine if there's a persistent deficiency doing a foliar every day might be necessary. If it's a calcium problem, you have issues before you even see the yellow new growth.

 

[Three Berries]

I imagine if there's a persistent deficiency doing a foliar every day might be necessary. If it's a calcium problem, you have issues before you even see the yellow new growth.

Such issues as what? I had slow, stunted growth. As the plant got bigger then the leaves started to yellow.

The CaCl2 should not be used every day generally per the instructions in foliar feed. Once a week until the problem goes away they say. 4 tbs per gallon which puts it near 1200 ppm for foliar feeding.

I'd be adding this to my nute mix but I'm only water every three days now. Any delay and the yellowing advances further into the new growth of the day. As it is my well water has some Ca in it for the nute mix base.

 

[ButterflyEffect]

Such issues as what? I had slow, stunted growth. As the plant got bigger then the leaves started to yellow.

The CaCl2 should not be used every day generally per the instructions in foliar feed. Once a week until the problem goes away they say. 4 tbs per gallon which puts it near 1200 ppm for foliar feeding.

I'd be adding this to my nute mix but I'm only water every three days now. Any delay and the yellowing advances further into the new growth of the day. As it is my well water has some Ca in it for the nute mix base.

I thought calcium issues manifested prior to the signs. Once you see the deficiency, it's already caused damage, or so I was told.

I'm still eager to see how well it works, although I'd much rather get to the root of the problem, such as raising the humidity in veg. It was simply too hot in the room, causing the VPD to be out of whack, especially feeding at 800-1000ppm. Another issue, for me, was letting them get too big in the solo cups. Even if I feed twice daily. Although I could test cutting the ppm down for 2 feeds on smaller plants I'd rather get them transplanted sooner. They do more than well enough in 1G containers through harvest, especially with 3 daily feeds, but they don't tolerate being rootbound that young for some reason. Defs all around, Mg most notably.

 

[Three Berries]

I had humidity low issues all fall and winter until adding the Ca. Had to put a couple small towels in the veg but the flower tent with the HPS I needed three big bath towels.

Since then for the most part the humidity takes care of itself and the fans are cycling at VDP of .98-1.10 if just left on auto. Not using the HPS though. Flower has a little flow all the time. But what really tricked everything into work is I put in additional lights and run them as heaters. keeps everything around 77f-80f. I'm sure summer will be different.. First summer with a flower tent.

I wonder about VPD and lights out. Anybody ever filmed the plants with video at night to see if they're growing? I don't worry until it gets to 805 but the temps are usually in the 60fs. They seem to stay around 70% or so with some fan cycling.

But would it be worth the efforts to drop the humidity when lights off to get a good VDP number?

 

[Three Berries]

And I was watching some of the good Drs videos and he was talking about VPD and the flower buds. Saying the flower buds, with the more mass, they get hotter internally and especially at the top of the plant.

 

[Broggemann]

I'm not sure Dr.Bugbee did the cannabis community a favor with his "calcium is king"-statement...

Imho that's clearly a potassium deficiency and has nothing to with calcium.
I had problems with LEDs, VPD and unhealthy plants for more than two years, and one thing I learned:
potassium is massively underrated.

 

[ButterflyEffect]

I had humidity low issues all fall and winter until adding the Ca. Had to put a couple small towels in the veg but the flower tent with the HPS I needed three big bath towels.

Since then for the most part the humidity takes care of itself and the fans are cycling at VDP of .98-1.10 if just left on auto. Not using the HPS though. Flower has a little flow all the time. But what really tricked everything into work is I put in additional lights and run them as heaters. keeps everything around 77f-80f. I'm sure summer will be different.. First summer with a flower tent.

I wonder about VPD and lights out. Anybody ever filmed the plants with video at night to see if they're growing? I don't worry until it gets to 805 but the temps are usually in the 60fs. They seem to stay around 70% or so with some fan cycling.

But would it be worth the efforts to drop the humidity when lights off to get a good VDP number?

Those are good numbers. What are your main flower lights? LED?

I'm working on new controllers now that have a photosensor that, when it's dark, will use a different set of code that lowers the humidity to match the cooler dark cycle temps.

I've been fortunate that I have full environmental control, at least in flower. I use misters that turn on via a solenoid. Veg is another matter. I haven't yet deployed a full-on controller in there yet, which is why I suspect I was having issues.

 

[ButterflyEffect]

I'm not sure Dr.Bugbee did the cannabis community a favor with his "calcium is king"-statement...

Imho that's clearly a potassium deficiency and has nothing to with calcium.
I had problems with LEDs, VPD and unhealthy plants for more than two years, and one thing I learned:
potassium is massively underrated.

Who has the K def? My plants or Three Berries? I'm still trying to get a handle on recognizing deficiencies.

And yeah, the calcium thing has thrown me off for a while now, as well. I started to realize that even after telling people that I was in mostly perlite, they were giving me advice as if I were in soil. Upping the Ca when you're in a low CEC medium like I am just makes the Ca antagonize everything else. I was told you can't reach toxic Ca levels but you can most certainly mess with nearly everything else due to how competitive Ca is.

 

[Three Berries]

Who has the K def? My plants or Three Berries? I'm still trying to get a handle on recognizing deficiencies.

And yeah, the calcium thing has thrown me off for a while now, as well. I started to realize that even after telling people that I was in mostly perlite, they were giving me advice as if I were in soil. Upping the Ca when you're in a low CEC medium like I am just makes the Ca antagonize everything else. I was told you can't reach toxic Ca levels but you can most certainly mess with nearly everything else due to how competitive Ca is.

Mine was not K. That's what I was thinking though. But both the Langbeinite and the Miracle Grow have plenty.

My lighting now for flower is 2-85w square with red LEDs and 1-100 w square. And two 50w FS cobs for aux light/heat. Veg currently is 2-65w LED and a 50 w FS cob for heat. I target high temp at around 85F but when that gets triggered the humidity drops out.

Sometimes I run the humidifier on flower at startup. But really don't have to as when the lights are off the humidity nears 80%. The veg tent I mist with plain rain water on the plants when the lights first come on.

Both today were getting too low of humidity near the end of the day. Usually means time to water next lights on.

Since adding the Ca as I have the VPD during lights on is working great with just a few tweaks of peak temps. Summer the flower tent is going to be an issue with too high temp but there also is higher inside humidity too.

It's a daily tap dance. Yesterday I was gone when they went off and when the flower came on. All was well on auto after they settle down with the AC Infinity controller.

 

[ButterflyEffect]

Mine was not K. That's what I was thinking though. But both the Langbeinite and the Miracle Grow have plenty.

My lighting now for flower is 2-85w square with red LEDs and 1-100 w square. And two 50w FS cobs for aux light/heat. Veg currently is 2-65w LED and a 50 w FS cob for heat. I target high temp at around 85F but when that gets triggered the humidity drops out.

Sometimes I run the humidifier on flower at startup. But really don't have to as when the lights are off the humidity nears 80%. The veg tent I mist with plain rain water on the plants when the lights first come on.

Both today were getting too low of humidity near the end of the day. Usually means time to water next lights on.

Since adding the Ca as I have the VPD during lights on is working great with just a few tweaks of peak temps. Summer the flower tent is going to be an issue with too high temp but there also is higher inside humidity too.

It's a daily tap dance. Yesterday I was gone when they went off and when the flower came on. All was well on auto after they settle down with the AC Infinity controller.

Might have been the plants I was originally talking about in this thread. I'm pretty sure it was K looking back at them now.

It's a tap dance indeed. That's why I designed the controllers so I didn't have to manually tweak each room constantly. Now I get to focus on the other headaches.

 

[f-e]

Field tests from a number of sites looked at K, finding it did nothing for cannabis yield. A surprising result after seeing other flowering crops respond well to it. The test sites covered most soil types, from sand to loam. There was no measurable response. I think they went to 200ppm.
I myself came out of coco to get away from the 100ppm or so it seems to add to solution. It was stopping me getting the Ca and Mg in that I wanted. That was Canna coco. Canna feeds tend to hover around 160ppm K but their coco feed is more like just 60ppm. They seem to know what I had to discover.
We used to see K a lot in the HID days, but since LED the typical issues related to water transport are rarely seen. With other elements more likely to be causing similar burning patterns. I'm not sure I have seen anything fixed with more K, in years?

 

[ButterflyEffect]

Field tests from a number of sites looked at K, finding it did nothing for cannabis yield. A surprising result after seeing other flowering crops respond well to it. The test sites covered most soil types, from sand to loam. There was no measurable response. I think they went to 200ppm.
I myself came out of coco to get away from the 100ppm or so it seems to add to solution. It was stopping me getting the Ca and Mg in that I wanted. That was Canna coco. Canna feeds tend to hover around 160ppm K but their coco feed is more like just 60ppm. They seem to know what I had to discover.
We used to see K a lot in the HID days, but since LED the typical issues related to water transport are rarely seen. With other elements more likely to be causing similar burning patterns. I'm not sure I have seen anything fixed with more K, in years?

IMO, it's more something blocking or antagonizing K as opposed to adding more K to some unknown benefit. In my situation, I believe it was a combination of a high VPD and too much added Ca for no good reason. I think you're the one who pointed out that my original problem that started this thread was likely a K issue. Would K be affected by too high a VPD?

 

[f-e]

Some waffle follows:
The two could look similar. With low RH moisture is lost from the guard cells (the lips) around the stomatal openings. Closing them. Giving the problem of reduced fluid movement.
K deficiency also shows when the stomata close. K is one of the regulators for their size.
With a good environment a low K level could restrict fluid movement, which would show at the leaf extremities where moisture was being lost and not replenished, concentration the EC there, and giving subsequent burning signs. This is going to be more likely on the larger fan leaves that are reaching out under hot lights. Drier extremities.
With low RH the effect is more holistic. Drooping is likely and issues not so bound to the outer reaches.
Both are a lack of fluid movement. Which can be addressed in various ways.

 

[Broggemann]

Field tests from a number of sites looked at K, finding it did nothing for cannabis yield. A surprising result after seeing other flowering crops respond well to it. The test sites covered most soil types, from sand to loam. There was no measurable response. I think they went to 200ppm.
I myself came out of coco to get away from the 100ppm or so it seems to add to solution. It was stopping me getting the Ca and Mg in that I wanted. That was Canna coco. Canna feeds tend to hover around 160ppm K but their coco feed is more like just 60ppm. They seem to know what I had to discover.
We used to see K a lot in the HID days, but since LED the typical issues related to water transport are rarely seen. With other elements more likely to be causing similar burning patterns. I'm not sure I have seen anything fixed with more K, in years?

Dont take it personal, I like your enthusiasm.
But you're posting and writing so much, and often all that's left is confusion.

It's about ratios, not ppms.
As ButterflyEffect pointed out.

You need more K under LED, because you need more Ca and have to keep the ratios.
If you look up FloraFlex, FrontRow, Athena, PerfectGrower... they are all feeding way above 300pm. In Veg!

Mine was not K. That's what I was thinking though. But both the Langbeinite and the Miracle Grow have plenty.

If I look at you're pics - that's definitely not calcium related...
You can keep doing what you're doing, but I'm pretty sure you will get problems soon (purple stems, leaf/tip clawing, etc).

 

[ButterflyEffect]

Some waffle follows:
The two could look similar. With low RH moisture is lost from the guard cells (the lips) around the stomatal openings. Closing them. Giving the problem of reduced fluid movement.
K deficiency also shows when the stomata close. K is one of the regulators for their size.
With a good environment a low K level could restrict fluid movement, which would show at the leaf extremities where moisture was being lost and not replenished, concentration the EC there, and giving subsequent burning signs. This is going to be more likely on the larger fan leaves that are reaching out under hot lights. Drier extremities.
With low RH the effect is more holistic. Drooping is likely and issues not so bound to the outer reaches.
Both are a lack of fluid movement. Which can be addressed in various ways.

It sure seems to back my theory of a high VPD causing a K def.