Light burn or nute burn?

Outdoor plants in Ocean Forest, just one is showing this, Mr E Pupil, which is the furthest along in flowering (other just started last week, really late this year) I was goin g to give this one a small does of Grow Big because of the rapid leaf yellowing and saw these leaves. Have given all 3 maybe a quarter dose of Tiger Bloom a few times in the past 6 days or so. If it were burn from Tiger I'd be surprised, since this is maybe a month into flower, and I always give a quarter of the suggested amount when I do feed to avoid nute burn. I bring up sun as well. There are aluminum window frames on the storage shed this sits in front, and about 6-8 feet across same thing on the side of our day room. and at certain times of day does reflect sun. Single leaf pic is when I noticed it with the necrotic looking spot, then saw the other similar spots. Aside from that leaf, the only other location is in the other pic, near the top. Thoughts?

Been searching this site and googling, not finding any photos with this kind of spot, and most reports on nute burn has it affect the tips and edges, not spotting like this. Not finding a match looking at pics of deficiencies either. Still debating on feeding 1/4 does of Grow Big to address the yellowing. BTW haven't fed in 4+ days, just water til runoff since, and today is the first day these spots showed up

They look like spill marks to me. Something dripped on those leaves causing the marks

Skiderbee said:

They look like spill marks to me. Something dripped on those leaves causing the marks

Click to expand...

My thoughts as well.. looks like rusty water drops or something

Not that I'm aware of. Been out in the sun, no nutes or chemicals for 5 days, just PHed water. What is real odd is within an hour of those necrotic spots showing up, those areas were dry and crumbled to the touch

obijohn said:

Not that I'm aware of. Been out in the sun, no nutes or chemicals for 5 days, just PHed water. What is real odd is within an hour of those necrotic spots showing up, those areas were dry and crumbled to the touch

Click to expand...

That would strongly suggest something got on the leaf. Any nutrient or pest cause wouldn't result in the spots crumbling to dust in hours.
Sure seems like a splash of something or other

The only thing else i could think of that would cause brown rusty spots is either calcium or magnesium defiecency.. but there"s no yellewing i can see..

These examples are cal. def.

You ph’d your water “yourself” and spilled it on the leaves. And can’t figure out why you have an acid burn on the leaves? I think Your fine bro. Ph lockout is easy to tell. Same as toxicity. They really go hand and hand. Ph falls Wack. Plant feeds on the wrong amounts of certain nutes. Locking her out. If not being able to feed at all.

More or less worry if issues continue to move upward or transfer into new growth. At that point you could decide if it’s mobile or immobile. But I really think you just spilled some water. When you ph down. Your adding acid to your mix. Raw acid. Ever get that shit ina cut? Or rub your eyes by mistake after playing around with it. It only happens once. Promise that.
I rarely hear about people having to add alkaline. Iv never even opened my bottle. So idk shit about that. I just know not to keep them side by side and never ever mix the 2.

add acid to water. Never add water to acid.

DrOgkush said:

You ph’d your water “yourself” and spilled it on the leaves. And can’t figure out why you have an acid burn on the leaves? I think Your fine bro. Ph lockout is easy to tell. Same as toxicity. They really go hand and hand. Ph falls Wack. Plant feeds on the wrong amounts of certain nutes. Locking her out. If not being able to feed at all.

More or less worry if issues continue to move upward or transfer into new growth. At that point you could decide if it’s mobile or immobile. But I really think you just spilled some water. When you ph down. Your adding acid to your mix. Raw acid. Ever get that shit ina cut? Or rub your eyes by mistake after playing around with it. It only happens once. Promise that.
I rarely hear about people having to add alkaline. Iv never even opened my bottle. So idk shit about that. I just know not to keep them side by side and never ever mix the 2.

add acid to water. Never add water to acid.

Click to expand...

Anything is possible I guess. But I don't water the top of the plant. I fill a 2 gallon water can with water and 4-5 drops of PH up (tests to around 6) and water the bottom of my pots, so not sure how it could happen.

Also, it had been 4 days since I did this before the spots suddenly appeared. If they did within a day of watering I'd take another look at it

I’ve seen these spots on my outdoor plants multiple times. I’m not 100% positive but I’m pretty sure it’s caused from a water droplet sitting on the leaf for awhile when it’s a hot day and is in direct sunlight.

The water kind of magnifies the suns rays and causes the leaf to burn under the water droplet. I wouldn’t worry about it too much just try not to get anything on the leaves on the real hot days. You can always shake the branches a bit if you do happen to get it on the leaves.

I couldn’t see this being ph up that’s on the leaves unless your mixing it outside by your plants but I would assume most people mix that stuff inside and have it diluted before giving it to the plants

GrandaddyPurp x OG said:

I’ve seen these spots on my outdoor plants multiple times. I’m not 100% positive but I’m pretty sure it’s caused from a water droplet sitting on the leaf for awhile when it’s a hot day and is in direct sunlight.

The water kind of magnifies the suns rays and causes the leaf to burn under the water droplet. I wouldn’t worry about it too much just try not to get anything on the leaves on the real hot days. You can always shake the branches a bit if you do happen to get it on the leaves.

I couldn’t see this being ph up that’s on the leaves unless your mixing it outside by your plants but I would assume most people mix that stuff inside and have it diluted before giving it to the plants

Click to expand...

Yeah, I mix and test PH in the kitchen sink, then step outside and water or feed. Up until flowering began I would literally wash my plants daily with the shower setting in my spray nozzle. Did this in the middle of the day/sun, no burn. If it were some kind of insecticide or something, I would expect burn

GrandaddyPurp x OG said:

I’ve seen these spots on my outdoor plants multiple times. I’m not 100% positive but I’m pretty sure it’s caused from a water droplet sitting on the leaf for awhile when it’s a hot day and is in direct sunlight.

The water kind of magnifies the suns rays and causes the leaf to burn under the water droplet. I wouldn’t worry about it too much just try not to get anything on the leaves on the real hot days. You can always shake the branches a bit if you do happen to get it on the leaves.

I couldn’t see this being ph up that’s on the leaves unless your mixing it outside by your plants but I would assume most people mix that stuff inside and have it diluted before giving it to the plants

Click to expand...

That's an old-wives tale and if true, my outdoor garden plants should be covered with burn marks.

Try if for yourself, take a hose to your plants on a sunny afternoon and see what happens.

The water droplets don't maintain their spherical shape and the point of focus is not on the leaf. Water is also a fantastic heat sink; even if the droplet shape was focusing light to single point on the leaf, it wouldn't generate enough heat on the leaf surface. The only exception is that some hairy leaves can potentially "suspend" a water droplet at just the right distance above the leaf which both focuses the light on the leaf and the water can't cool the leaf since it's not making direct contact.

The primary reason to avoid watering mid-day is to minimize evaporative losses.

obijohn said:

Anything is possible I guess. But I don't water the top of the plant. I fill a 2 gallon water can with water and 4-5 drops of PH up (tests to around 6) and water the bottom of my pots, so not sure how it could happen.

Also, it had been 4 days since I did this before the spots suddenly appeared. If they did within a day of watering I'd take another look at it

Click to expand...

Why are you using ph up if your ph is already set at 6? What nutes are you adding? Are you checking ph after you mix? If your in soil. You have a buffer. You shouldn ph anything. Essp alkaline. And if your organic. Double no.

DrOgkush said:

Why are you using ph up if your ph is already set at 6? What nutes are you adding? Are you checking ph after you mix? If your in soil. You have a buffer. You shouldn ph anything. Essp alkaline. And if your organic. Double no.

Click to expand...

Tap water is around 8 PH or a bit above. I can use it out of the tap because, as you say, the soil will buffer. Tiger Bloom drops it down to 2 PH, so I use PH Up to get it to around 6. Grow Big raised it up a few points, so PH down to get to 6-ish

obijohn said:

Tap water is around 8 PH or a bit above. I can use it out of the tap because, as you say, the soil will buffer. Tiger Bloom drops it down to 2 PH, so I use PH Up to get it to around 6. Grow Big raised it up a few points, so PH down to get to 6-ish

Click to expand...

Your mixing up and down?

Are you following the steps in schedule? When I used fox farm trio. My ph balanced at 6.2

No, I am not mixing Up and Down. As I move away from Grow Big on a regular basis I'll be primarily using Up with Tiger Bloom.

I don't follow the FF schedule exactly. I've learned to use at least half the recommended amount, usually even less, or the plants will get burned. They seem to like smaller amounts of nutes. I pretty much just use Grow Big and Tiger Bloom past years to keep things simple. The Beastie Bloomz and other [powders never seemed to do anything but empty my wallet. I water every other day, alternating with feeding so nutes about twice a week

Honestly re looking at it. Def has a rusty look.

if your ph is fine like you say
Your nutes are balanced as you say
You never spilled on the leaves as you say.

rust fungus would be the last option no?

DrOgkush said:

Honestly re looking at it. Def has a rusty look.

if your ph is fine like you say
Your nutes are balanced as you say
You never spilled on the leaves as you say.

rust fungus would be the last option no?

Click to expand...

I hope not, but based on looking at photos of plants that have it, looks different IMO