Help PLEASE some sort of deficiency

[StudentGreen]

For some reason, I’m only seeing the deficiency under these new led lights and not under the hps lights.
The light ppfd is around 1200 under led so can’t be that, plus I’m supplementing with around 1300 ppm co2
Maybe I’m under feeding?
Here’s pics of them under led and hps

 

[StudentGreen]

I’m using canna coco professional plus and the canna nutrient line, my last nutrient ppm was around 700 which is around 1.4ec

 

[LoveGrowingIt]

I believe I see several deficiencies... Mg, Ca & maybe some P. Not sure about that last one. So, it looks like they're somewhat underfed.

For some reason, I’m only seeing the deficiency under these new led lights and not under the hps lights.

LED lights seem to need plenty of Mg.

 

[StudentGreen]

Yh I think so too, I have bumped up the nutrients to around 900 ppms, hopefully that does the trick….

 

[MrCannabisExplains]

Hey Student, that's quite the grow you've got going on! Impressive set up!

Ok, so you're running in coco, what is the percentage of Ca and Mg in your nutrient line? Or are you using any extra Calmag? Cause you definitely have a Potassium deficiency. The chlorosis starts at the tips and moves inwards on the blades, and forming necrotic(black) spots.

This can just be from under feeding them, as they do look rather light.

But also, applying too much calcium and magnesium can cause a potassium deficiency, and the K/Ca and K/Mg ratio should always be kept above 2, meaning the concentration of K should be at least two times higher than the concentration of Ca or Mg. So that’s something to consider if you often lean on using a CalMag additive in your grows. However, you want to keep the ratio below 10, as too much K can hinder the absorption of calcium and magnesium... so don't try to just add a potassium heavy mix to fix your problem. ;)

Of course, you may want to also look at the nitrogen and what source it is. Too much ammonium (NH4+) can interact negatively with the plant’s uptake of calcium, magnesium, and potassium, particularly when the NO3- (nitrate)/ NH4+ ratio is low. The N/K ratio is also crucial when plants are passing from the growth or vegetative phase to the generative or flowering phase.... and your looks to be about 2 weeks into flower, yes?

Just somethings to consider. For now, i'd say to get some nutrient water volume in there to flush out any nutrient or pH issues out, while upping your EC, say 1.8-2.0 for plants that size in coco... and CO2 supplementation. ;)

Now, about the differences between your HPS and LEDs. Those are 600s, yes? Do you know where your PPFD is sitting with them compared to your LEDs? Are they drinking as much as your LEDs? Similar sizes? What's their colour like? I think all your HPS pics are too orange to tell, can you grab a true colour pic of them?

Since you're just forming buds, the cooler(blue) PAR LEDs might've been helping their plants form more vegetative growth in the first 10 days of flower, as they doubled in size. So if they're bigger and more pale than your HPS plants, that may be in part for the difference between them. Do you have even intake air and temperature distributions between them?

Just curious as to why they'd be running so differently. Any more specific details would be helpful in trying to figure this out with you! :)

 

[StudentGreen]

Thanks man, appreciate that!

So I’m using the canna coco nutrient line which is a 2 part line for the whole cycle, canna a and b and the same canna a and b is used throughout the whole cycle, I will be changing this on the next one so I can dial down my ratios better when I add perlite for drainage.
Back to this crop, canna suggest that when you have soft water, to add their canna calmag and bring the ec to 0.4 before adding other nutrients.

My water comes in at 0.2 so I add the required amount to make the solution 0.4 ec.
Checked my local water supply and these are the numbers

Then I add my base nutrients and other additives.

Now I checked my last nutrient res and I’m pretty sure it was around 1.2 ec which is very low so I think that sure did have a big part to play.

Dr Bruce bugbee, a plant scientist states you should always under feed rather than overfeed and I may have took that too seriously lol.

Now with regards to the ratios of K/Ca or K/Mg or any other ratios I honestly don’t have a clue. I just roughly follow the feed chart and try to keep my ph now around 6.0 and 5.8 previously in veg.

I’ve not really done much in depth research on nutrients yet as obviously there are so many aspects to growing good quality shit but I’ll definitely need to if I want to dial things in.

Yh exactly 2 weeks, today is day 15 after the flip and I have just fed them at 1.8 ec so hopefully will see a difference.

Yes 600w hps lights at around similar ppfd to the leds, ranging from 900 to 1300 ppfd at canopy.

I have however only brought in the leds like a week ago to help control temps as only hps was just too much. So the leds were introduced on around day 7 of flower, not sure if the sudden change may have interrupted them in any way.

Room is sealed with no intakes or exhausts, I run air conditioning, humidification, dehumidification and heating for full control.
Air flow is pretty good so air temps are even around the room. However, canopy of the hps are a little hotter obviously with all the infrared.

At the moment I’m running my room at 28 d c and 60 percent humidity.

I don’t have any normal lights in the room but I’ve just taken a few leaves from under the hps and placed them under the leds and have realised they are very similar lol, the orange light is very misleading, I would say the leds still do look a little worse off but I’d only know if I placed the led light over the canopy of the hps I guess.

Thanks for the help by the way, really do appreciate it!

 

[MrCannabisExplains]

Ok, so there a lot of unpack here.

Your water looks like it has a lot of Ca in there already, so depending on the levels in your nutrients, that may be enough without the Calmag addition. I would suggest you focus more on your volume and EC right now. I would water at about the 1.8-2.0EC that i mentioned, and water for about 40-50% leachate once to help flush out any imbalances in the media.

And i definitely agree with Dr Bruce bugbee, it's always better to feed a BIT light, than to accidentally over feed and lock up nutrients! However, i agree with you that you've overdone it. ;) Your ladies should always be a nice medium green, only getting darker once they're really putting on biomass. They should look like this about this stage of life.

And while i wouldn't say that i'm glad to hear that the plants under your HPS are doing similarly unwell, it's good to know that the crop health is consistent across the crop. :)

 

[StudentGreen]

I see, do you think it may be wise stopping the calmag and instead use something that will just give me magnesium?
I know that canna coco a and b have some calmag but not sure how much, they don’t state that information as far as I’m aware.

I’ll definitely leach them out with the 1.8 to 2.0 ec

Damn looking at that picture and simultaneously at my plants makes me want to shoot myself, guess we have to make these school boy errors to get better…

 

[MrCannabisExplains]

I see, do you think it may be wise stopping the calmag and instead use something that will just give me magnesium?
I know that canna coco a and b have some calmag but not sure how much, they don’t state that information as far as I’m aware.

I’ll definitely leach them out with the 1.8 to 2.0 ec

Damn looking at that picture and simultaneously at my plants makes me want to shoot myself, guess we have to make these school boy errors to get better…

Dude, don't beat yourself up over it! We all have to start somewhere! :)

A healthy plant has a healthy root system. And a healthy root system is a balanced root system! We just have to figure out how to achieve that, then it's smooth sailing... until you change something, then the learning begins anew! :D

And there isn't a back label that has the nutritional breakdown? That's odd.

I would suggest going without Calmag for a feeding or two. Coir has a moderate to low CEC of approximately 50 meq/100g, but it can hold onto calcium, magnesium, and iron, preventing these nutrients from being absorbed by plants. However, since it looks like you have a bad K def, i would say minimizing your Ca might be more beneficial for K absorption, than compensating for the CEC of coco with Calmag, as both are needed in much lower concentrations than potassium.

Or you can try half strength Calmag. The chemistry of the root zone is hard to estimate. Lol You can always collect and test the leachate to get an idea of what the EC and pH of the nutrient water of the root zone was... BUT singular leachate testing should be taken with a grain of salt, as you can get outliers. Leachate testing should generally be done within a scheduled program, for consistent results.

Just make sure to get enough nutrient water volume through her to flush out the problem! And just make sure you allow them to dry down after you give them that drenching. :)

And also don't forget, you could just be starving her and she'll get all the K she needs at proper EC levels. Lol Sorry, i just went back to look at the pics again. Sometimes when you're having issues, it's best to Keep It Simple - make sure you have proper EC and pH levels, and watering volume and frequencies.

 

[StudentGreen]

just realised something and this makes me think this discolouration could be light stress???

I have 1 plant that never got transplanted as I didn’t have the room for it, and it looks so much better….. only difference is it gets way less light.

 

[StudentGreen]

This little plant has just been left at the bottom so doesn’t get no where near as much light but the green is just so much better…..

 

[StudentGreen]

An and yes I know of the thrip damage…. I’ve ordered loads of ambleyseius swirskii, a predatory mite to tackle the issue.

 

[MrCannabisExplains]

I wouldn't write that off to too much light immediately, as cannabis can use 1500 µmol m2/S or more with proper conditions. Your greener plant is smaller, which could just be cause you're not feeding enough, that's the only plant getting the proper EC for her size. ;)

 

[StudentGreen]

Yh that’s what I was thinking because I am matching the ppfd with the co2 pms, was just trying to rule all the things out.
The only other thing that I see as a potential problem is my ph drift, I always set at 6.0 but as my nutrient tank sits there, the ph always rises.
My water does have chlorine and I leave a water pump to recirculate the water with a waterfall effect to evaporate the chlorine but that should only raise ph for around 48 hours as the chlorine should be fully evaporated by then.
I think co2 also evaporates from the water which also raises the ph but even after a week of the nutrient tank sat there, the ph still rises.
Ah writing this also made me realise another problem I’ve faced recently, my nutrient tank temp was around 30 degrees Celsius so not sure if this could have affected nutrient uptake.
I think water temp affects co2 evaporation too so could be another reason for ph drift but regardless of water temps, I am seeing a lot of ph drift.
Ph drifts up by around 0.3 every 24 hours, is this normal?

 

[StudentGreen]

Ah don’t think the ph drift would make sense actually, the little plant would have the same issues if it was the case

 

[LeafLoomer]

man, plants always find a way to thrive

 

[StudentGreen]

man, plants always find a way to thrive

Yh hope these find they’re way soon!

 

[MellowRello]

I believe I see several deficiencies... Mg, Ca & maybe some P. Not sure about that last one. So, it looks like they're somewhat underfed.


LED lights seem to need plenty of Mg.

Why do you say that? when the photos are of the tops of the plant only?
Where do you see a Ca deficiency? Where do you see a P deficiency? Do you have any idea why you are talking about?

 

[Sunasun]

Poor light stressed improperly watered plant.

 

[MellowRello]

For some reason, I’m only seeing the deficiency under these new led lights and not under the hps lights.
The light ppfd is around 1200 under led so can’t be that, plus I’m supplementing with around 1300 ppm co2
Maybe I’m under feeding?
Here’s pics of them under led and hps

Are they lollipopped? Why are we looking for possible mobile nutrient deficiencies at the tops of the plants? This thread is hilarious.