Heat stress?

[MedScience]

One of my two mothers just started doing this yesterday, it has been pretty hot outside and I have been hovering around 82-84 deg temps in the room the past week. Everything was fine and then within one day this happened. I am hand watering in coco and the pH is at 5.5. She is under 4 T5s so the lights dont put out that much heat. Any ideas? The leaves feel pretty brittle, is this just a case of heat stress, or do I have some deficiency? I flushed the plant with pure water yesterday, and the leaves arent as droopy as they were before, but the color has gotten worse. Thanks for any help.

 

[MedScience]

More info:
EC is at 1.2-1.4, nutrients are PBP Grow 8ml, Liquid Karma 5ml, Silica Blast 1ml, Cal-Mag 5ml, using RO/DI water and buffering to 5.5 with gen hydro pH up

 

[LlamaSchool]

Well between the "rust" coloring and the "claw"-like leaves (tips down, curling) I wonder if you could have some sort of pH issue or toxicity of a certain nutrient. I have heard of problems with salt buildup in coco.

These are all just thoughts to research more, not concrete diagnoses.

 

[MedScience]

Well, I am not entirely sure that my pH is at 5.5, my meter broke and I sent it back to the manufacturer, awaiting a replacement now. I am however using the exact same amounts of additives and Ph up so I assume it is at 5.5 or maybe a bit higher. I have not changed my nutrient mix specifically because I don't have the pH meter right now and there is no way to eyeball it.

 

[reverev313]

wow bro the tips aint burnt so try more nuts if they start to burn flush

 

[LlamaSchool]

I actually DO see some burnt tips in those pictures, no?

pH meters are great but you would be wise to also grab a liquid pH test kit. Many experienced growers still use these. They sell for about $6 from GH and come with a dropper of pH reagent and a vial for mixing a few drops with your water.

 

[MedScience]

Yeah the tips are pretty crisped, I am thinking it has to be something with the nutes but I am using the exact same mix on another mother right next to this one, different strains, this one having the problems is an Alaskan Thunderfuck, the healthy one is some Diesel cross and it looks fantastic.

 

[Green-ninja]

How old are your plants?

 

[headimonster]

when in doubt, flush.....how often do u hit them with Cal-Mag, it almost looks like a Mag Toxicity...

 

[MedScience]

This is a mother grown from a clone purchased 4-5 weeks ago. I am using 5mg CalMag per gallon of RO water, I flushed her yesterday with about 5 gal of pure RO, no additives.

 

[Phillthy]

yes i have had heat stress manifest itself in this manner.

 

[MedScience]

Should I do anything like trim back the affected areas or will the plant heal itself?

 

[mexilandrace]

dont trim it, and no the effected leaves won't improve but if you cut them off it's likely the normal leaves will start showing signs, Aassuming it's not heat related.

never cut off sick leaves, no one cuts them off in nature, the plant has mechanisms to cope, let them cope

 

[headimonster]

i have had my room go up to 100 before and never seen any sorta heat stress like that....it usually robs the plant of nitrogen once they try and get too hot and start to curl down and try....i just noticed some rust-like spots on your leaves that maybe a toxicity...

 

[MedScience]

After the flush, it looks better, no more rust spots, but the new growth has very thin spindly leaves. Everything looks better overall but still in no shape to take clones. Thanks for all the advice, I will keep an eye on her and put up another picture if it gets worse again. I hate not knowing exactly what I did wrong since I have been trying to get everything dialed in...

 

[richyrich]

I highly suggest you read a post I started last month.

http://www.icmag.com/ic/showthread.php?t=124986

Also, feed pH your nutes at 6.0 for coco. And, I would suggest using coco specific nutes. Nearly all the experienced coco heads here will tell you this.

 

[montehierba]

flushing is key
great looking plants

 

[mexilandrace]

After the flush, it looks better, no more rust spots, but the new growth has very thin spindly leaves. Everything looks better overall but still in no shape to take clones. Thanks for all the advice, I will keep an eye on her and put up another picture if it gets worse again. I hate not knowing exactly what I did wrong since I have been trying to get everything dialed in...

that spindly shit means a nute or ph problem.

I already forgot and I could re-read but am lazy, they are in flower or veg?

dial in the ph before you flower them if you can, and ph freak out plants still clone okay, takes a bit longer, but if it is a time thing, you can do it.

plants have totally different needs in flower than in veg, even ph range changes a little with most, so if you need to flower now, you will be surprised how they act.

 

[richyrich]

Everything was fine and then within one day this happened.

Is this when your pH meter broke and you started winging it?

 

[MedScience]

The meter broke last Fri, almost 2 weeks ago. This is a mother plant in veg under 24 hr light. I will try to up the pH but cannot do that until the replacement arrives, hopefully any day this week. I will try to track down a liquid kit before then.. I am using PBP Grow on this plant, PBP Bloom Soil formula on plants in flower, I dont want to change the nute brand since I will be switching to RDWC on my next crop.