Rust spots

Hi all, problems with one of my cheesecake autos in lightmix with Bacs nutes. Basically all 3 are same strain, 2 seem to be going ok but one has developed rust markings and crispy leaves throughout the plant. I mix the nutes in a large container and water all of them from it so all have been getting the same nute doses, I switched to bloom nutes 4 days ago as strech seems to have stopped. Currently the have 1ml of bac bloom (which I believe is 6-5-6) per litre and pH down to 6.4. the water is tap water which is left out for 24hrs prior to use. Temps 26/27 Rh 45%, 4 inch passive intake and 6" rvk extractor.

Did this happen quickly? Or over a period of time?

if it happened quickly it’s most likely pH swings due to the media getting too dry/wet. In my experience it’s too dry when I see damage that resembles yours.

Another clue is the randomness of it which again happens when the pH swings too much.

When peat based soil dries the pH drops and the EC spikes.

How much water and how often and what is the size of the container?

Nutty sKunK said:

Did this happen quickly? Or over a period of time?

if it happened quickly it’s most likely pH swings due to the media getting too dry/wet. In my experience it’s too dry when I see damage that resembles yours.

Another clue is the randomness of it which again happens when the pH swings too much.

When peat based soil dries the pH drops and the EC spikes.

How much water and how often and what is the size of the container?

Click to expand...

They are in 6.5l pots, giving each plant around 1.5l or untill 10% run off every 3/4 day approximately

Nutty sKunK said:

Did this happen quickly? Or over a period of time?

if it happened quickly it’s most likely pH swings due to the media getting too dry/wet. In my experience it’s too dry when I see damage that resembles yours.

Another clue is the randomness of it which again happens when the pH swings too much.

When peat based soil dries the pH drops and the EC spikes.

How much water and how often and what is the size of the container?

Click to expand...

Hmmm as to how quickly, I would say around 1 week

Nutty sKunK said:

Did this happen quickly? Or over a period of time?

if it happened quickly it’s most likely pH swings due to the media getting too dry/wet. In my experience it’s too dry when I see damage that resembles yours.

Another clue is the randomness of it which again happens when the pH swings too much.

When peat based soil dries the pH drops and the EC spikes.

How much water and how often and what is the size of the container?

Click to expand...

What is the likelyness that she will finish?

Greenthumbgrower1986 said:

What is the likelyness that she will finish?

Click to expand...

Watering Seems ok. Although once they start budding the water demands sky rocket. For me it’s like clock work. Every 2 days I water. Even a few hours late can cause issues. So it’s either 3 or 4 days. Maybe she got a little too dry one day?

From my experience the pH markings show up in a couple of days after stress. Doesn’t take long at all.

Yea she’ll finish no bother! It’s all about maximising the yield you get.

So your bloom feed is a 6-5-6? That’s pretty balanced and could feed that until the end. Most blooms have too little nitrogen to sustain green leaves until harvest

Nutty sKunK said:

Watering Seems ok. Although once they start budding the water demands sky rocket. For me it’s like clock work. Every 2 days I water. Even a few hours late can cause issues. So it’s either 3 or 4 days. Maybe she got a little too dry one day?

From my experience the pH markings show up in a couple of days after stress. Doesn’t take long at all.

Yea she’ll finish no bother! It’s all about maximising the yield you get.

So your bloom feed is a 6-5-6? That’s pretty balanced and could feed that until the end. Most blooms have too little nitrogen to sustain green leaves until harvest

Click to expand...

Thanks alot for the help, I'll make sure I don't leave them dry for too long

Nutty sKunK said:

Watering Seems ok. Although once they start budding the water demands sky rocket. For me it’s like clock work. Every 2 days I water. Even a few hours late can cause issues. So it’s either 3 or 4 days. Maybe she got a little too dry one day?

From my experience the pH markings show up in a couple of days after stress. Doesn’t take long at all.

Yea she’ll finish no bother! It’s all about maximising the yield you get.

So your bloom feed is a 6-5-6? That’s pretty balanced and could feed that until the end. Most blooms have too little nitrogen to sustain green leaves until harvest

Click to expand...

She appears to be going bad very quickly, other 2 plants seem fine

Greenthumbgrower1986 said:

She appears to be going bad very quickly, other 2 plants seem fine

Click to expand...

Are they all in the same size of pot? Do you lift before watering?

The other two are much bigger and are fine. Could be user related or just weak genetics. I have noticed that once autos go slightly wrong it’s hard to stop them. They are in such a rush to finish compared to photoperiods.

Im gonna go out on a limb and say that it’s not hungry. It’s most likely too much food or watering issue.

The foliage health is just a symbol of the root health

Nutty sKunK said:

Are they all in the same size of pot? Do you lift before watering?

The other two are much bigger and are fine. Could be user related or just weak genetics. I have noticed that once autos go slightly wrong it’s hard to stop them. They are in such a rush to finish compared to photoperiods.

Im gonna go out on a limb and say that it’s not hungry. It’s most likely too much food or watering issue.

The foliage health is just a symbol of the root health

Click to expand...

They are all in same pots, all same genetics, all fed the same. I lift pots to feel weight before watering. I have a pot of just dry soil in back of tent so I can compare weights.

Maybe humidity swings or light intensity or calcium def cause you seem to be watering properly but looks like the one plant is getting cooked tough call

Baccamsauce said:

Maybe humidity swings or light intensity or calcium def cause you seem to be watering properly but looks like the one plant is getting cooked tough call

Click to expand...

Can't imagine it being to do with environment as she is the smallest and others aren't showing any signs of light/heat stress

Update pic

Not rust spots or typically Calcium Deficiency that is Phosphorus Deficiency. Increase your base nutrients and drop your pH to 6.0. Pluck off badly affected leaves and monitor for progress.

calvin.m16 said:

Not rust spots or typically Calcium Deficiency that is Phosphorus Deficiency. Increase your base nutrients and drop your pH to 6.0. Pluck off badly affected leaves and monitor for progress.

Click to expand...

what nutrients are you suggesting I give? I've stopped at 2ml per litre of Bacs 6/5/6 because I started noticing nute burn. I'm a noob but convinced it's some type of lockout