help with recurring issue with SOME strains

[AJY]

hi there,

I have been growing for some time. I usually have a couple of strains on the go. Some need no care , others some.

I have for some time been having this same issue with 'certain' strains. All are within the same 7' x 7' x 7' space under a SpydrX Plus Fluence lamp.
I got in 5 gal air-pots. original solid mix was 40% happy frog soil 40% coco coir 20% worm castings. This is however my 3rd grow in the pots without changing the soil.
I was told at this point it is basically like growing in pro-mix. so, that being said...

I keep getting this slightly clawed , light green look to the leaves as they mature. Lower leaves are flatter and a darker green. look alot better.
PH around 6.7 ish ... using Medi-one and Tribus & a bit of fulfil acid. Bush Dr. Cal-mag. PPM around 600 for veg. lots of wind . temp 70 C humidity a bit low @ 60.

I am just wondering what you guys think ? my PBB & Slurricane are no hassle grows...but the frosted cherry cookies seems to like to play with me in this fashion.
Next grow I try fully living soil - or as close as I can get ...but for now I want to di into wh the heel I keep seeing this same issue ... with a couple of strains.

Thanks alot.

 

[PK1]

temp is 70c or 70f? That a big difference

 

[AJY]

70 F oops. sorry.

 

[PK1]

get your temps up to 80f+, i assume all your light settings, heights are all correct.
about your questions, i was told that some genetics are like that.

 

[AJY]

I try not to heat the top of my plants up too much, so I keep my lamp eight or more inches above the top of the plants. 18 hours a day veg.
I really ! appreciate your response obviously...it just makes sense from what I see. I have been growing for about 30 years, but the last time I grew was about a decade ago it was in Hydro and it was super easy.
Since I've been in pots this issue has been plaguing me a little bit. not that hydro would change this situation - as you suggested some strains may just behave this way.

I want to make sure I'm not hurting my girls before they go to flower. I uploaded a video so you could see the light set up.

 

[PK1]

i'll take a bit for the servers to encode the video so it can be watched. What type of light is it?

 

[AJY]

it is a Fluence SPYDRx. I am reading an average of 550 PAR across the canopy.

 

[mysticepipedon]

That pH is too high. I think it is locking out some micronutrients.

 

[AJY]

Perfect thank you. That makes sense as I got used to the idea of growing in a living soil, what I'm actually more like in a pro mixed style situation now since all the nutrients are gone from the media. I will drop my pH down to 6.2 see how that goes. Could be what I am missing will see. Temp raised up to 78 F for veg.

 

[PK1]

do a slurry mix and find out what the readings are.

 

[AJY]

Excellent . I have never done this before. I looked up the instruction here on this site. Need some RO first . My PH meter is reading close to what I feed them...6.8-70 .
I generally PH 6.7. thanks again I try this and get back to you when I have. meantime I drop the PH to 6.2. should help alot.

 

[PK1]

do a 1:1 ratio of soil and distilled water unless your water is dead center 7.0
also, if your water gets to 6.8 ph than why are you using ph down at all?? your soil reduces the ph automatically so it is available to the plant.

Lets get those readings and see where it is at

 

[Anthem]

Raise the light to about 18" or more. They cannot handle that much light yet. And for what it is worth that does not appear to be a Fluence Syder 2i lights. You can double check on the fluence website

 

[AJY]

right on. My water PH is approx. 7.4 at start. after nutrient mix down to about 6 ish. I raised the light so there is now approx. 425 PAR at canopy top.

 

[AJY]

do a 1:1 ratio of soil and distilled water unless your water is dead center 7.0
also, if your water gets to 6.8 ph than why are you using ph down at all?? your soil reduces the ph automatically so it is available to the plant.

Lets get those readings and see where it is at

ok. finally obtained distilled water.

Followed the instructions from this site for slurry mix.
My PH after 20 mins was 6.5 and the same after 45 mins. ( My PH soil test meter tells me the soil has a PH of closer to 6.8 or 6.9 )

 

[tobh]

with LEDs you want those temps up ~80F. You're seeing VPD issues on top of it due to what the others said, potential lockout from pH being out of whack. Easy to recover from both.

 

[AJY]

with LEDs you want those temps up ~80F. You're seeing VPD issues on top of it due to what the others said, potential lockout from pH being out of whack. Easy to recover from both.

interesting. I had no idea the temps 'should' be higher for LEDs. I was apprehensive getting up to that temp. Now to get my PH down. My soil is very old in this case and is somewhat akin to proMix at this point. Thank you.

 

[tobh]

interesting. I had no idea the temps 'should' be higher for LEDs. I was apprehensive getting up to that temp. Now to get my PH down. My soil is very old in this case and is somewhat akin to proMix at this point. Thank you.

yeah it's a definite discomfort thing with LEDs initially. It's counter to what we learned with HIDs. The primary reason is LEDs don't heat up the leaf surface as much due to typically not having as much infrared light, so to ensure that the leaf surface is warm enough for stomata to open we have to drive up the environment temps.

Ideal temps/RH under LED are variable, but I typically shoot these numbers in veg:

Air temp: 82F
Leaf Surface Temp: 79F
RH: ~60%

This should give a VPD of ~ 1.14 kPa, which ensures the plants are able to transpire at optimum levels.

 

[AJY]

yeah it's a definite discomfort thing with LEDs initially. It's counter to what we learned with HIDs. The primary reason is LEDs don't heat up the leaf surface as much due to typically not having as much infrared light, so to ensure that the leaf surface is warm enough for stomata to open we have to drive up the environment temps.

Ideal temps/RH under LED are variable, but I typically shoot these numbers in veg:

Air temp: 82F
Leaf Surface Temp: 79F
RH: ~60%

This should give a VPD of ~ 1.14 kPa, which ensures the plants are able to transpire at optimum levels.

crap. ok. that is some GOOD stuff. I had NO idea about this. I use Plant therapy to help keep pest & mildew issues at bay. thx again. I start feeding a lower PH && get my temps up[ to 80 for sure.

 

[tobh]

crap. ok. that is some GOOD stuff. I had NO idea about this. I use Plant therapy to help keep pest & mildew issues at bay. thx again. I start feeding a lower PH && get my temps up[ to 80 for sure.

really, the primary temp you want to look at is your leaf surface temp. if you don't have one, pick up one of those cheap infrared temp guns and measure the temp across different leaves at the canopy level and average that #. Adjust the air temp to whatever is needed since leaf surface temp is the one that matters most (you want it close as possible to 79F as that's the maximum transpiration golden zone), and RH is the second most important number.

Also, if you're on android, download the VPD Calculator app. It's super helpful if figuring out what your VPD actually is without having to do the math yourself and it has a little chart that indicates ideal kPa for plant cycle. Just another part of the LED learning curve, you got this.