Bright Yellow Patches & leaves Turning Down, & Some plants turning up! - Any Advice?

[JonnyWiz]

Hi all, this is my first grow, sort of a fumble my way through job! my plants are into their 7th week of flowering now, we only started using nutes since week 4, but only in light amounts

the plants are generally healthy but over the last few days one has had problems with the leaves turning down & bright yellow almost dayglow patches on the dark green leaves, any ideas what could be causing this?

some of the other plants leaves are turning up, as in the 3rd picture, is this a symptom of heat stress? using a 400w HPS light, bout a foot away from the tops with a small fan circulating to cool abit

Any advice would be appreciated

Thanks

[stinkyattic]

Exactly!
Your plants are showing two of the three most common symptoms of heat stress: Upcurled edges from a high temperature:humidity ratio, and actual burn patterns on the leaves where what would have been a mild fertilizer problem has turned into necrotic burned areas. The last symptom would be an overal yellowing of the plants.

Fill out the troubleshooting form, and tell us as much as you can about how your room and exhaust is conficgured, and the lights.
Finally, can you get a close-up of the curled-UNDER leaves in pic #1? There are two or even three things going on there (heat, a possible Mg issue, and the possibility tyhat the plant is either rootbound or N overdosed) and we can figure it out with more information.
You're close to harvest I see so it will mostly be heads up kind of info for next time. Honestly the plnats look like they had been doing very well for a long time.

[JonnyWiz]

Thanks for the info stinky, im not too clued up on our exact setup! lol we got a whole job lot 2nd had kit, have attached some more pics, sorry can only take them with my iphone, have taken a pic of the extraction we have too

1.5m2 grow tent
E-indoor
E-soil,
E-
CSL-Miraclegrow
SCL-
SCLR-
E-bathroom tap
E-Source water pH
HRT-)
E-4 months
E-Aarde A&B Nutrients (A - 8-0-11 B - 2-4-10) 1.5ml per 1ltr + Bud booster
E-
E-400w HPS 1ft away from plant
E-75/50)
HD-Reservoir temperature
E-
E-12/12
E-an extractor with filter(came with kit)

We also have a small radiator in the tent on 24/7 as our nights are nights are nearly freezing

[stinkyattic]

What brand of tent? Have you ever heard of hydrohut syndrome?
How big are your pots? Have you ever flushed your plants, and checked the pH?
It also seems that the worst of the stripe damage is in a line, as if it was all caused during the same time period, but that the stressor may no longer be there. Have you recently raised your lights, or did you at some point give them too much feed?

[JonnyWiz]

Not sure what brand of tent it is, got it all in a job lot,

Pots are 3 gallon ones I think, have recently (3 weeks ago) upgraded them as think they were become rootbound, never really flushed the plants, check the PH from time to time but only with some electronic prong thing you put in the soil, but said it was close enough to 7 all the time, what is the best way to test the PH?

We did raise the lights a couple of inches when we saw the leaves turning up etc, what sort of hight should a 400w be from the tops? they leaves are still remaining folder up though, should they relax & go flat again?

dont think we have ever given it too much feed (all the others got the same amount and they seem fine) it is just the 1 plant that has these extreme yellow patches, the others are all green, but on some of them the leaves are folding upwards

we are at week 7 of flowering now so you are correct that this will be for my knowledge the next time round where we will use a proper course of nutrients, and not just randomly giving them some like this time ;)

[Dutch Pimp]

We did raise the lights a couple of inches when we saw the leaves turning up etc, what sort of hight should a 400w be from the tops?

400MH...16 inches....400HPS 12-15 inches...above the canopy. IMO. This zone should be at 78 degrees (ideally) with good, fresh air flow.



Not sure what brand of tent it is, got it all in a job lot


I hope, it's not a HydroHut Death Tent?

[JonnyWiz]

hmm so my light appears to be the right height from the plants,

Here are some more pictures, the 1 plants seem to be getting worse! what could be causing the yellow patches? it is only near the top of the plant,

on the other plant the leaves are still curling upwards and there seems to be brownish speckles appearing on the leaves (cant really get these to show on the photos

What is this death tent of which u speak?

[stinkyattic]

Can you get us a runoff pH number as soon as possible?
The HydroHuts made about 1-2 years ago outgassed toxic fumes that killed plants.
But you have other stuff going on, like the taco leaves that say your heat is too intense and your humidity too low.
Those stripes DO resemble damage from a severe Mg deficiency but don't look quite right to say for sure. Even so, making up a spray bottle of 1/2 teaspoon epsom salts per quart of water with one drop dish soap, and LIGHTLY misting the plants with it, NOT ON THE BUDS!!!, will halt the spread of Mg def if that is what it is, and not harm the plant if it isn't.
But get that pH number asap. You may need to do a heavy flush very soon.

[JonnyWiz]

Hi, sorry bit of a n00b, how would i get the PH rushoff? not sure all that stuff will be available form me to do, still learning the ropes

Do you think it wil see out the next 2 weeks? should be ready to harvest by then

thanks in advance

[Weedhound]

How about a photo of the hut itself?

[Weedhound]

You need an accurate way to measure ph.....even strips or drops from a pet store would be ok....but NO ph adjusters for fish.....just the testers.

Then water your plants and collect the water from the bottom......test ph.

Your issue has Got to either be ph or hydrohut I would think.......

[Weedhound]

http://boards.cannabis.com/plant-problems/153522-soil-runoff-ph-flushing-correct-lockouts-why-how-do.html

[JonnyWiz]

right, I may not be able t get some Ph testing paper for a few days! I have CHE he'd with my battery powered reader (has 2 prongs that stick in the soil) this read ph7,

What else can I try to try and bring this baby back, don't want it getting ruisdd with only 6 weeks to go,

What I think is weird is that it is only on 1 of my 6 plants, so surly it can't be the tent?

[DTRave420]

right, I may not be able t get some Ph testing paper for a few days! I have CHE he'd with my battery powered reader (has 2 prongs that stick in the soil) this read ph7,

What else can I try to try and bring this baby back, don't want it getting ruisdd with only 6 weeks to go,

What I think is weird is that it is only on 1 of my 6 plants, so surly it can't be the tent?

Like stinky says,the tent can be one of the problems...There was a total recall of HydroHut because the plastic interior was made with a compound that was proven to f**k up grows...Hope your plants feel better man...

[JonnyWiz]

right don't thnk it is the tent, I have now noticed that the yellow tips of leaves has spread to the main bud on the stem on one of the other plants, we are in week 7 so just flushing with water now so if it is a nutes deficiency we can't add anything to correct it! Just hope they will last another 2 weeks, will the condition be damaging the bud?

[Weedhound]

You're missing the point.....if the ph in your pot is incorrect it doesn't matter what you do....your plants will not be able to absorb any nutes. Shoot, where's that old .....brb

[Weedhound]

http://boards.cannabis.com/plant-problems/116304-another-ph-question.html

A great read on ph.....

[Weedhound]

It doesn't really look like a hydrohut death to me either.....usually the entire plant turns lemon yellow and then just folds.....I think the issue is your ph.

Your question as to whethere they will last until finish is unknown. Poor conditions create unhealthy plants. Yours are obviously not healthy. Unhealthy plants tend to develop disease such as root rot etc....which can destroy your plant with 48-72 hours.

That's why growers like Stinky and myself don't slide along praying things will hold "just a bit longer" (because I've lost that game more than once) but try to make sure that plant doesn't GET into a situation where illness becomes much more likely.

[JonnyWiz]

Thanks for all the info so far guys,

Will be doing an accurate PH runoff reading later when i get home and will update the post, hopefully then we can correct it

[JonnyWiz]

Hello again, the plants are getting worse..

I have now done an accurate soil runoff ph test, came out at 6.6, tested my tap water and was 6.8

So what are my options to bring the plant back to health, as now into week 7 of flowering I cant add any nutes,

Bit worried about one of the other plants now, is getting the same bright yellow patches on the tips of the leaves around the buds, on the really sick one (in the pictures) the problem doesnt seem to have spread to the buds yet and remains on the larger top leaves, although the problem is getting worse

Any help would be apreciated

Thanks

[Weedhound]

That's spot on perfect. Nope, that's not your issue then. How do the buds look. Like they'll be ready in a week?

[Weedhound]

2 questions

Does the problem seem limited to the plants and leaves closest to the light? If you look at the plant.....at the parts NOT directly exposed to the light are they normal? Or is it evenly on all they leaves regardless of where they are in reference to the light?

Are the plants still getting super cold at night? That'll getcha by killing off small roots.

[Weedhound]

Also I'd STRONGLY consider a good root product like Cannazym which will help stave off root rot until you can get them harvested.

[JonnyWiz]

Yeah the buds are looking good, first grow so nothing to compare them with but they are close to finishing, all trichomes are cloudy, no amber yet though (maybe a random 1 or 2)

we have 6 plants, 2 rows of 3 with the light in the the middle, the problem has occured on the front left & front right plants, not the ones so directly under the light (we have now raised it a little and seems to have stopped the taco effect on the leaves) and is happening all the way round the plant so pretty even

Yep temperatures are around freezing at night, although we have a portable oil style radiator in there on 24/7 im sure it gets cold still, damm battery in temp gauge has packed up, will replace and measure it properly tonight

[knna]

Although i agreed the initial Stinky's diagnosis, after knowing temps are 75/50 and the lamp 1ft away now i have doubts.

Now i believe its a micro's deff, likely Cu or Mn (or both) due the high ph. What do you think, Stynky?

Anyway, at this stage there is little to do, and its more a matter of curiosity :stoned:

[Weedhound]

Well if he can get the lower temps it it will definitely help.....other than that....I';dd add Cannazym just to make sure to keep the roots healthy and tough it out.

[stinkyattic]

Your pH is slightly low, but your REAL problem is that your plants are freezing cold- are they sitting on a cold cement floor? Cold soil will show MUCH MUCH worse lockout symptoms than soil at the optimal 70'F. Also, you are running MG soil.

To keep from spreading:
Stabilize temps at NO LESS than 60'F night!
Get pots up off cold surfaces
Withhold water- let the pots get rather dry between waterings, and improve pot drainage/root zone oxygenation.
FLUSH to bring pH to 6.8 with tap water. You also probably have fertilizer buildup from running a pre-ferted dirt plus liquids, so the flush will take care of both problems.

But your big issue is temperature.