Eagle claw during week5 flower--to flush or not to flush

[feelingfactory]

Hey fellas. I'm about to start week 5 of flower and there are downward-curling leaves (eagle claws) that haven't gone away since week 3. The problem was more pronounced after I had to leave town for a whole week and overfeeding/nuteburn occurred under the care of a friend.

Pretty sure it is from N overdose (dark green, glossy, clawing), but not all plants show symptoms. Furthermore, these clawing leaves have no resin production going on while the normal looking leaves on other branches/stems do.

Problem worsened from May 5 to 8, during which nuteburn occurred(unsure which day). Clawing and burning has stopped since then, but the clawing has not recovered.

Should I flush for 1-3 days to let the clawing leaves recover? Or run a lower ppm (lets say 850) for 1-3 days?I'd be thankful for and would appreciate any comments and suggestions. Thanks all!


HYDROPONIC

How long has this problem been going on? Roughly 2.4 weeks
Are you growing in a PVC grow tent? Yes- 4x4
What system are you running? GH Waterfarm x8 w/ controller+res
What STRAIN are you growing? 7 DP Blueberry + 1 DNA Rocklock
What was the establishing technique? All from seed
What is the age of your plants? Three months
How long have they been in there mixture they are in now? Since 3/27 (rockwool to hydroton veg transplant)--48 days.
How tall are the plants? Around 3-3.5ft
What PHASE are the plants in? Starting Week 5 Flower
What Technique are you using? I don't know what this question is asking. I LSTed and feed via drip rings.
What substrate/medium are you using? Hydroton
What is the Water temperature? 67-68F
What color are your roots? Some white, but sorta stained brown from nutrient solution.
What Nutrient's are you using? GH Flora Micro, Bloom.
How much of each nutrient are you using with how much water? 1 part Micro to 2 parts Bloom. Currently at 1230ppm
How often are you feeding/How often are you giving nutrients? Refill whenever the res runs low, drip runs 24/7.
If flowering, when did you switch over to using Bloom nutrients? Used Lucas since veg.
What order are you mixing your nutrients? First Micro, then Bloom.
What is the TDS/EC/PPM you are using? 1230, started at 1000 (week 1) and slowly moved up. Spiked to 1450-1500 for 2 days or so under care of a friend.
What is the pH of the "Tank"? 5.8-5.9
How often are you testing your pH/PPM/EC/TDS? Daily 3x
Are you sure your calibration is correct on your equipment? Yes
When was your last watering? Drip rings run 24/7.
What is your water temps? 67-68F
When was your last feeding change? Nope
How often do you clean your system: Not often. Last time was 1 week ago. Before that, it was first day of flower.
What size bulb are you using? Hortilux Super HPS enhanced spectrum 1000w HPS. (LU1000B/HTL/EN)
How old is the bulb you are using? First time use in Flower.
What is the distance to the canopy? Originally 7+ inches, now 13+ inches since CoolTube installation on 5/12. Original reflector and CoolTube glass can be comfortably handled with bare hands.
What is your RH Factor(Relative Humidity)? 45-56%
What is the canopy temperature? Mid to high 70s when lights on.
What is the Day/Night Temp? Day: mid 70s, Night: 70 +/-2
What is the current Air Flow? No idea, but my intake and exhaust are strong enough to suck my hand into the ducting.
Tell us about your ventilation, intake exhaust and when its running and not running ? Intake/Exhaust run together, and are almost always on.
Is the fan blowing directly at plants? Intake blows low (across lip of buckets) while 2 small fans blow indirectly from above the canopy.
Is your water HARD or SOFT? Soft. RO Water at <14ppm
Has plant been recently pruned, cloned off of or pinched?
Thinning and mild pruning since week 2 until middle of week 4. I know I shouldn't have, but it had to be done. One stem pinched because it grew past the light (week 4). It's doin' great.
Have any pest chemicals been used? No.


Photos:

May 5

May 9

May 12

May 14 (half-way up an unaffected stem.)

 

[bombadil.360]

hello man,

how does one flush in hydro? never grown hydro before...

anyway, it does look like nitrogen toxicity.

chill with the nutes for a while... and when you re-start them, try to feed with something very low on the nitrogen end.

good luck

 

[feelingfactory]

Hey fellow LotR fan! (I assume that's where you got Bombadil)

To flush in hydro, either:
1. get rid of all liquid in the buckets, res, and controller, then fill with water.
Or
2. gradually lower ppm by pouring in water (no nutes) over time as res/controller levels drop.
and then let the system run for however long one deems necessary.

I guess what I should also ask is: is it possible for clawed leaves to return to normal?

Still don't get why only the stretchy/sativa-y pheno of DP Blueberry have clawing while the other 2 phenos are doing great.

 

[sparkie480]

my dieselrella nydxc99 is doing alot of the same thing i am not sure but i think heat and air i am keeping my fan more on mine good luck

 

[statusquo]

Sativas maybe require less nitrogen since they are spindly with less mass/vegetation? I would say flush - this late in flower couldn't hurt might help. Your leaves should be starting to yellow at this point anyways (imo).

 

[RugerBaby]

too much N

 

[bombadil.360]

hello feelingfactory, yeah, I'm a nerd who loves good old Tolkien

thank you for explaining hydro flushing to me

if indeed it is nitrogen toxicity, looks a lot like it, they can surely bounce back to normal, I've seen it happen before but only in veg, not sure if they will fully recover while in flower, but they will get better once the problem is corrected.

you are growing from seed, right? so you have individuals growing there, all will react a little bit different to the excess N.

I would agree with sparkie480 if I didn't see a plant in the back corner of your pic also getting clawed. plus your canopy temps are not excessively hot either.

and as statusquo says, many sativas don't like a medium that is too hot in nutes.

they should bounce back to health soon...

good luck!

keep all the orcs at bay too

peace

 

[feelingfactory]

Thanks for the fast responses guys. As per your suggestions to ease up on feeding, I just dumped out the controller+res and filled them with RO water to dilute the buckets from 1260 to around 600 or so. Going to let this run for maybe 2 days. Hopefully it won't screw up bud and trich production...

Really annoying how two phenos from a same strain could differ this much in nutrient preference. Going to have to re-think which clones I should stick into the next recirculating water farm system...

I'll update with any signs (or lack) of recovery. Hopefully this will help the next poor shmuck who runs into the same problem

 

[feelingfactory]

Quick update. It's been over 24hrs since I dropped ppm big time. Leaves still look about the same. Going to give it 2 more days, but from what I have gathered on ICMag, these leaves will not recover. In this case, should I just feed nothing but GH Flora Bloom w/ no Micro for like a week or so? I really do not want to interrupt bud/trich production by starving the plants of P/K/Mg/etc.

 

[hazy]

No, those leaves won't flatten out. Hopefully new growth looks flatter.

You really need that micro, I would not leave it out. Since there's NOT too much N in the nute solution you use, I really doubt if you have such an over abundance of N that would cause a 'toxicity'. Maybe we could think that if you just gave them a big shot of gh grow too.

Can't someone in California, since it's sort of legal there take some leaf samples to a lab and test so we know what causes this claw?

 

[feelingfactory]

Thanks for dropping in, hazy.

There was very very severe nuteburn that did occur. I should snap some pictures of it. Hell, the budding leaves at the tops even turned a pasty off-white and the larger leaves below them have big splotches of bright angry yellow. I think that's when the DP Blueberry sativa phenos began to really show the dark green waxy claws. Too bad the leaves are gonna be stuck like this. No new leaf growth happening at the tops. Maybe the nuteburn fried them. 1500+ppm when plants can only take <1200 sure ain't a good thing!

The Micro does have a lot of micronutes in there that I don't want to miss. You're right about not ditching it, hazy. I'll just resume normal feeding (1240ppm) and forget about running this 600ppm 'recovery'?

 

[Hash Zeppelin]

this is my most often given advice, and it should work, and generally solves most dwc problems.

do a CLEAREX flush and start with balanceed flower nutes, at a lower ppm. You should clearex flush every two weeks like that, and at the last flush add only clearex and leave it.

Also tie that branch back way from the light with a string to something. it is too close. it is getting to hot.

Also make sure your ph meter is calibrated. That is a biggie.

 

[feelingfactory]

Will do, Hash Zeppelin. One question though: for a ClearEx flush, do I first completely drain the buckets/res/controller, fill it up with RO+ClearEx, run it, drain it all, and lastly refill with nutes? Or can I just add ClearEx straight into the existing nutrient solution, let it circulate, then drain and refill with fresh nutrient solution?

I've done the former prior to the start of flower to get rid of salt buildup (from rinsing hydroton with really really hard water) that was screwing up my plants. What is the reasoning behind a flush every two weeks? Clear out the multiplying microorganisms & potential buildup of underused (nute) elements?