Upcurl - perplexed

[BudLove]

Hey Bro's,

I'm a little concerned at what I'm seeing with my latest batch of lovely ladies.... I'm aware that the normal cause for upcurling is heat stress, however I am having a hard time accepting that based on the following conditions:

Strain: SER Chronic
Method: DWC (Blaze's recirc config)
Light: 400W HPS
Age: 17 days from seed
pH: 5.85
Water Temp: 68.1F
EC (us): 1344
PPM: 670
Air Temp: 71F
Humidity: 55
Light hours: 24/0
Distance from light: 12inches

As you can see, the above is close to the ideal conditions (and what I've used countless times in the past without issue). I thought at first it might be 'light burn' from the lamp being too close, but thought with a 400W this could not possibly be the case as with 1kW's.....

Leaves do NOT feel crispy and are showing no signs of nute burn. They are actually a lighter green rather than the normal dark shade we see with most over-nutrient rich solutions.

However, everything I've read, and found searching, targets heat stress to be the main cause.... which I dont have. Second is humidity, which I admit 55 is a tad low but not low enough for me to expect this. Lastly, I considered possible nute strength, as these are only 17 days old from seed.... but I didnt think a ppm of 670 would be high enough to stress the plant due to water salinity.

Any ideas folks? I am going to work on lowering the ppm today incase that's the cause... other than that, I believe lowering the air temp any further will actually hurt these ladies.

Thanks for any assist' you all can provide!
BL


Pic of the sick lady:

 

[BudLove]

Here is an additional pic of her out of her HPS 'home'...

As you can see - there are no signs of nute burn that I can see...though I still consider myself a newb and am way open to comments!

 

[Hans Wurst]

i just can guess around too although i don't know much more than you already do. i only saw signs like this when they were too close to the lamp or if they got too much nutes. as you are using a hydro system it may be a little more difficult to regulate the nutes.
the last guess i can make is that you got a bad pack. sometimes genetics do things out of control. but as these seeds are originally from serious seeds i would not guess that they send out a "bad pack".
my advice: check nutes twice again and if this won't work you may contact seroius seeds as they have a number on a every pack they sell.

hope this helped you somehow. and ooh man i have to train my english a lot more.

 

[yohomz]

Did you transplant them recently? Could be stressed from that... When I grew chronic this happened to a couple of mine as well, but not til a much later stage.

 

[BudLove]

Hmmm... well it appears that it is not getting worse (which is good). I am running FloraBloom nutes and they tend to be on the stronger side - though I didnt think the current EC was all that high.... plus, I was under the impression that chronic was a heavy eater and could take it.

However, I know for a fact this can not possibly be a heat problem...as temps have not gotten higher than 73F (measurement taken at highest point of plant).

So the only thing left is nute strength... that would also explain why as they're getting bigger the issue is going away.

Just 'one of those things' I guess...

BL

 

[DIGITALHIPPY]

heat stress.
need to lower temps, increase ventalation.
its not 73. i dont care what you say, thats heat stress, and only one way to get it.
maybe your light is too close to the plant...12-18 inches..is optimal for 400hps.

 

[BudLove]

Hey Digital,

I know bro - this is seriously perplexing to me - as I've grown plenty of batches in the past and have several journals under a diff name.

Truth is I place the temp probe on TOP of the highest leaf on the plant. I would have no reason to falsify the temp readouts as my obvious quest is to solve what the fuck is going on.

The temps I listed ARE accurate. The range, from what I've logged in my spreadsheet, is from 68F-74F. It's still very chilly where I'm located so the ambient temps outside of the grow room range from 54F-70F.

One note - I am NOW seeing the lower leaves begin to turn slightly crispy to the touch and brown in the center. This is indicative of nute burn, and most likely caused by my upping the EC to as high as I took it far more quickly than I should have (at plant age of 13 days).

I realize perhaps your experience of this behavior is solely related to heat stress - but upon my research I have learned that it can be cause by that OR nute burn/stress. Since I have not transplanted these (DWC from seed), and my temps are indeed within the range I have stated - I am left with no other solution other than nute burn.

Sad you 'dont care what I say'... I may not have your post count with this account, but I surely wouldnt lie about something so trivial.... Thanks for your input though - trust me, I'm banging my head against the same wall screaming HEAT STRESS...HEAT STRESS.... but it just can NOT be.

BL

 

[Ploum]

Hi,

I would have bet on heat stress too, but it could also be a RH stress, if your humidity level did change a lot of times in a short time period. Also does not look like a N burn.
My 2 cents.

Good luck.

 

[DIGITALHIPPY]

if the temps are what you say they are....
then you should add a fan to the room. maybe point it up towards the light...
an oscilating fan would be better then you could strengthen the stems aswell.
ive ONLY seen that side curl from heat.ive had it alot.
the plant could be getting a burn aswell. but thoes are different problems.
new pics of the leafs being brown/starting?

id give it a flush of RO (atleast a gallon) if you think it is a burn aswell...

 

[BudLove]

Thanks everyone....

I also already have an oscillating fan in the room. Trust me, this setup has worked for me countless times. I use a water chiller, maintain temps with an AC unit, use a 400w, RO water and recirc DWC.

This is why I'm kinda shocked at how these are behaving.

SO - although I disagreed about the heat, I decided to raise the light to 2 feet - 24 inches, above the plants. This is a ridiculous height but I needed to test this hypothesis myself.

It did NOT make a difference and if anything they are both getting slightly worse.

I then decided to simply remove the water from them all and replace with R/O water and only 2ml of FL per gallon (vs 4ml).... this is thus a flush and 1/2 the nutrients I had in the tub. I have also left the light 2ft above the ladies.

At this point it's a waiting game I suppose. I am now seeing that lower leaves are beginning to turn crispy and browning. I just can only hope the new growth does not suffer the same. I also hope that this curling goes away - otherwise I'm going to be sadly out of answers!!!! (which is kinda shocking)

Thanks!
BL

 

[BudLove]

One additional thing I've done - just to add to the fun - is a foliage spray with straight R/O water. I realize this may cause them to droop due to being in DWC already (possible over watering)...but believe that if this is caused by either heat (which I doubt as my current temp right now is 70.6F) or humidity (which is possible as it's currently 55%) - this will quickly shows signs of resolving both.

So now.... I wait.

BL

 

[Rosy Cheeks]

I'm banging my head against the same wall screaming HEAT STRESS...HEAT STRESS.... but it just can NOT be.

You know, sometimes you experience a phenomenon and it just shouldn't happen according to your growroom stats, but still it does.

The bottom line is, plants don't lie, and somehow they seem to signal heat stress. It may be because of the strain (they all react differently to different amounts of heat, light and humidity, etc), air humidity is one thing and the actual humidity (which is very important in this context, as Ploum pointed out) right between the lights and the plants another, air circulation within the growroom, etc. There are a number of almost incalculable factors you could have overlooked.

In any case, listen to your plants. If you pull away the lights, rearrange plants/ventilation in the growroom, increase air humidity, and THEN still experience the same phenomenon, that's when you should start to doubt the heat stress theory.

Instead of increasing ventilation, which will only lower the Rh, I would increase CO2 ratios in the growroom.

 

[BudLove]

Right on - I hear ya Rosy.... this is not the first time my ladies have stumped me.... I guess I was just always able to quickly isolate what was causing the issue and go from there.

Right now I'm running a 4inch Vortex inline fan for exhausting and wont be switching that out until ambient temps reach 79F for my 6inch Vortex to assist in keeping temps closer to ambient.

I believe that if this is truly a RH issue, the misting I just gave them should display some relief from the issue within the next day or two... that combined with the lower nute dose MUST do something to either improve or make worse the current issues.

Sadly, I never experienced this type of issue with Dr Chronic's cross or even Arjan's Haze... so I'm shocked that Serious Seeds Chronic would be this touchy.... sigh....

BL

 

[GET MO]

I think haze plants take heat well cuz theyr tropical, chronic might be a lil more sensative though-at least to heat.

 

[DIGITALHIPPY]

Thanks everyone....

I also already have an oscillating fan in the room. Trust me, this setup has worked for me countless times. I use a water chiller, maintain temps with an AC unit, use a 400w, RO water and recirc DWC.

This is why I'm kinda shocked at how these are behaving.

SO - although I disagreed about the heat, I decided to raise the light to 2 feet - 24 inches, above the plants. This is a ridiculous height but I needed to test this hypothesis myself.

It did NOT make a difference and if anything they are both getting slightly worse.

I then decided to simply remove the water from them all and replace with R/O water and only 2ml of FL per gallon (vs 4ml).... this is thus a flush and 1/2 the nutrients I had in the tub. I have also left the light 2ft above the ladies.

At this point it's a waiting game I suppose. I am now seeing that lower leaves are beginning to turn crispy and browning. I just can only hope the new growth does not suffer the same. I also hope that this curling goes away - otherwise I'm going to be sadly out of answers!!!! (which is kinda shocking)

Thanks!
BL

sometimes i need to raise my lights an abnormal distance for no apperant reason... im almost 48" away right now...

 

[onelov]

all tho it dose look like heat, and could be. a 2nd look at pic 2 show's on the bottem leafs what seem's to me to be a start of mg/ca lock out and maybe a lil n dif? witch is more then likely PH???

has your ph been stable at 5.85 or has it drifted below? i all ways keep mine at 6.0 and let it drift to 5.8 then raise back 6.0......

if i remember right low ph will all so do the leaf curl.

 

[BudLove]

Ladies and Gents... I am happy to report I discovered this cause, and it also somewhat has expanded my future troubleshooting of this type of sickness.

As I normally stick with the Lucas formula, I rarely (if ever) use Grow nutes nor additives. In this case I was using FloraBloom nutes....

Basically, the leaf curling was due to my rapid increase in nutes... too much increase as it ended up burning the plants. Now the interesting part is the plants did NOT show the normal signs of nute burn (dark green, etc)... this was obviously due to the lower levels of N being introduced... Yet, the nute burn was apparent based on the higher P K levels.

This apparently caused the leafs to curl, similar to heat stress...even though temps never got above 79F and the light was always 12inches + above the canopy.

Either way, once I did the flush, gave the ladies half the nute dose and just waited - the new growth has stabilized as well as the older leaves.

Just one to add to the ole memory bank....