Leaves bright yellow!

[roxy002]

Looking for some advice guys. I've read through previous threads but it seems that yellowing leaves can be a sign of all sorts of problems.

It's mainly the smaller new leaves that are turning bright yellow, almost fluorescent.

The strange thing is, There is 2 different strains and only one strain has been affected. I have 3 Feminized Big Bud, and one Feminized Confidential Cheese. Only the Big Buds have the yellow leaves.

Here's some details:

10 litre pots
Media = Coco
Nutes = Canna Coco A & B
EC = 1.8
PH = 5.8
600w HPS, approx 14" from plants

They are sat in 1 x 1 metre tent and I give them a good feed every couple of days, when the coco is starting to feel a bit lighter. The drainage is OK, so I don't think root rot is the problem. What, I did do differently though, the last feed I used lime juice to lower the PH, was this a bad idea? But the confidential cheese is fine. The coco has been used once before, but it was dried out, as was all the left over roots in the coco. Up until the last feed they have been healthy. I gave them a flush yesterday with straight tap water, PH at 5.9 but no improvement yet.

Any advice appreciated guys, cheers.

 

[nightfun]

Hi, I've never heard of using lime juice. That could be the problem. Flushing them is a good idea. Before watering in the future, be sure the growing matter is dry not just the top. You don't want to risk root rot but having wet medium all the time.

 

[roxy002]

Hi, I've never heard of using lime juice. That could be the problem. Flushing them is a good idea. Before watering in the future, be sure the growing matter is dry not just the top. You don't want to risk root rot but having wet medium all the time.

Can't remember where I heard to use lime juice, it was probably on the Internet somewhere. I'm gonna stick to using ph down in the future, but used lime juice as i didnt have any ph down at the time.

Suppose all I can do is sit back and wait. I'm just worried that it might get worse. These are mothers, so don't wanna lose them.

Also the tips of the bottom fan leaves have gone crispy brown, but only on the big bud.

 

[paulycali]

Is the yellowing plant on the outer area of the garden where less light hits. Yellowing from the top is usually from lack of light. Rarely an iron deffieciency. I think your plant just needs more light if its yellowing from the top down

Good Luck :)

 

[Scrappy-doo]

What are the ppm's of your nutes? I really doubt the lime juice was the issue. I've heard of people using that a lot to lower ph.

You did what you could by flushing them.

Letting them dry out can allow salts to build up and lock up the nutes. If you can't keep them wet consistently you might want to get some drip clean. It prevents salts from solidifying.

 

[phenotyper]

If you can't keep them wet consistently you might want to get some drip clean. It prevents salts from solidifying.

Agreed, drip clean is amazing. I use it in coco and hempys. However, do you have any idea if it has any effect on microbial life in the soil?

I'd also like to add that light bleaching, sulfur deficiency or toxicity, and potentially PH can all cause these issues.

 

[RIPP]

Looking for some advice guys. I've read through previous threads but it seems that yellowing leaves can be a sign of all sorts of problems.

It's mainly the smaller new leaves that are turning bright yellow, almost fluorescent.

The strange thing is, There is 2 different strains and only one strain has been affected. I have 3 Feminized Big Bud, and one Feminized Confidential Cheese. Only the Big Buds have the yellow leaves.

Here's some details:

10 litre pots
Media = Coco
Nutes = Canna Coco A & B
EC = 1.8
PH = 5.8
600w HPS, approx 14" from plants

They are sat in 1 x 1 metre tent and I give them a good feed every couple of days, when the coco is starting to feel a bit lighter. The drainage is OK, so I don't think root rot is the problem. What, I did do differently though, the last feed I used lime juice to lower the PH, was this a bad idea? But the confidential cheese is fine. The coco has been used once before, but it was dried out, as was all the left over roots in the coco. Up until the last feed they have been healthy. I gave them a flush yesterday with straight tap water, PH at 5.9 but no improvement yet.

Any advice appreciated guys, cheers.

Hi there

I'm not an expert but in my opinion your problem might be from low temperatures, also big difference between day & night temps.

btw this is how your plants might look after a week or two in flower.

 

[theHERBivore]

I have the same problem but my dwc water is at 69 degrees and ambient is 71 inside. Does anyone else have any guesses?

 

[SmokeyPipes]

That looks like Light bleaching or a possible Sulfur Defeciency based on the pics!

 

[RIPP]

That looks like Light bleaching or a possible Sulfur Defeciency based on the pics!

Thanks for your advice SmokeyPipes .
If you are correct my 300W LED (3W chipset) is too powerful and must be hang at least 2 or 3 meters from the canopy to prevent this massive light burn. This is really sad for me. is it possible to put some transparent cover or something else in order to reduce light / photon intensity?

 

[theHERBivore]

I run t5s in Veg n that's where its happening. It's pretty hard to light bleach with t5s isn't it ? I'm thinking micronutrient or some kind of temp adjustment since its only new growth but I run a modified Lucas at 1.5.10 with 5ml cal mag and a little liquid karma in ro water so all nutes should be there with a ph of 5.6 to 6. Wtf ?

 

[RIPP]

Here is another strain growing under the same conditions. :thinking:thinking

 

[nebulius]

is it me or do the edges of these leaves look a bit rigid? humidity or heat (high or low, big fluctuations) issues?

 

[onaeun]

Looks like light bleaching to me? 600w 14" from the canopy could cause this with high temps. Is this happening in the general area under your light? If so, then simple there's your problem. If not, you need to start looking into what the others have said

 

[theHERBivore]

Allright after mad research the picture i posted is the dreaded tmv or tobaccoo mossaic virus :( what a fing bummer. Chem strains r know to carry it and it only comes out when stressed. Thing is if your cloning and the plant juices get transferred to other plants/clones then everything has a chance of getting the mosaic virus. Chlorosis in the veins, looks like heat burn in some places and the infamous twisting leaf which can sometimes show blisters. Well I'm pretty sure that's my prob.. hope yours is just a nute deff. If all those signs are their and you see that trusty leaf as well its most likely tmv. Peace out happy toking.

 

[justiceman]

Yo I don't run canna coco A & B but I have run into similar problems. I honestly don't think its tobacco mosaic virus but I could be wrong.

If I were to take a guess I'd assume that your nutrient levels are running a tad bit to high in the medium. The yellowing new growth speaks sulfur def to me. Your nutes are not deficient in sulfur I think the plants are having a hard time pulling it or whatever else it needs. This is because the osmotic pressure is to high so the roots are probably having a hard time uptaking nutrition ESPECIALLY to new growth as that is the hardest place to pump water and nutes to.

I saw that you flushed. Maybe it wasn't enough? Just my 2 cents. Here's my plants that went through the same thing(I think)

Before nutrient lock out

During nutrient lock out

During nutrient lock out

After nutrient lock out

I ended up flushing two times in a row with Earth Juice wetting agent and Humic acid. 1 week recovery time before growth started to accelerate.

It got the job done. Here are the same plants nice and healthy. I say flush with humic acid and a wetting agent FTW. As for the DWC and such I would personally lower the nutrient concentration. The above pics have raised leaf fringes, twisted curling growth, and slightly burnt leaf tips. This all spells high salt content witch means low nutrient uptake.