Help identify leaf issue

[Burchell]

Hey folks,

First time poster, long time reader here.

I've been growing my first crop for a few months now and have been learning so much. Things have been going great up until a few days ago.

I've noticed an issue popping up on my leaves and was hoping someone may be able to help point me in the right direction.

My plants seem to be developing some rusty red spots on the upper fan leaves.

My plants are currently in week 5 of flower. I'm growing in FF Ocean forest with additional perlite added. I feed with Plant Prod MJ nutes as per their recommended feed schedual and ammend with cal mag periodically (although havnt done so in about 3 weeks - just forgot).

My grow setup is a 2x4 tent with 2 LED fixtures (185 true watts per light). I use a carbon filter and exhaust fan and a small desktop fan for air movement. Humidity stays between 45/50% during flower and temps stay between 18-25 degrees (night and day).

I cant see any pests of any sort.

My watering PH is typically 6.2-6.8.

I just added equal parts soil and distilled water (ph tested 7.0) and measured. Ph measures 6.4.

I dont believe I am over or under watering. I let the soil dry adequately before watering.

Any thoughts? Pics attached.

Thanks in advance for any input!

 

[Burchell]

I should also add that I flushed my plants last week as I was starting to get some clawing/downward canoeing and thought it may be possible that an N-toxicity issue could be popping up. I have since re-fed with a lower N feed - basically half bloom (10-30-20) and half finishing nutes. (4-31-37).

 

[MrSauga]

Have you been adding Calmag? It looks like it could use some of that. Those numbers look high for PK even in flower. Are you using full strength? Chances are the plant doesn't need that much N at this stage either.

 

[MrSauga]

ammend with cal mag periodically (although havnt done so in about 3 weeks - just forgot).

OK I see that now..ya get that back in.

 

[Burchell]

Thanks for the reply! I was thinking it may be cal/mag related. The plants were the healthiest looking plants I've ever grown up until recently. I pretty much forgot to feed cal/mag it over the last 2-3 weeks, which I had been using pretty much the whole way through.

 

[MrSauga]

OK good. Just keep an eye on the doseage for the nutes. Typically an NPK during flower would be similar to 0-5-6, or even a 1 on N. It changes based on the nute brand but yours look really high.

 

[Burchell]

I should also mention my feed ppm hovers around 900. I use bottled spring water as my well water is very high in iron and I use a softener.

My bottled water usually has a ppm reading of 75-250 depending on the bottle. I add nutes to get a final ppm of 900ish.

I top dressed my soil with a little bit of worm castings before switching to flower.

 

[MrSauga]

PPM numbers are good. The spring water is most likely why you need that Calmag. Pretty much used up what FFOF can give her.

 

[Burchell]

Makes sence to me. I grew from seed and started adding cal/mag about 4 weeks after germinating. I figured the FF had enough to get through the first chunk of veg, but would need to feed more eventually.

Had no issues until I forgot to feed it for a few weeks.

 

[MrSauga]

Well the leaves damaged wont repair, and you most likely are not seeing new growth, so just keep an eye on it, give it a good dose of calmag til the end and watch the progression doesn't get worse and you should be good!

 

[Burchell]

Perfect. Thanks for the advice!

 

[FelipeBlu]

I should also mention my feed ppm hovers around 900. I use bottled spring water as my well water is very high in iron and I use a softener.

My bottled water usually has a ppm reading of 75-250 depending on the bottle. I add nutes to get a final ppm of 900ish.

I top dressed my soil with a little bit of worm castings before switching to flower.

Concur on the CalMag. I would also use the bottled water with the lower TDS (75 ppm). Your softened tap water probably has too much sodium in it.

 

[MrSauga]

Your softened tap water probably has too much sodium in it.

Sweet, that never even clicked in.. I love this place!

 

[FelipeBlu]

How’s it growing Burchell?

 

[DramaMonkey1]

I am experiencing some of this on my leaves as well, but I thought it was burning from my lights. I had my plants at 18 inches and I noticed some damage happening, rustic like on the edges, and bigger rust like marks on the leafs. I'll post pictures below. I brought the plants to a height of 24inches and didn't notice a difference. I brought them down to 30 inches and I've noticed it not happening as much.

That being said, I am also growing in FoxFarm Ocean Forest, but I have only been using Fox Farm Big Bloom, Big Grow, and Tiger Bloom with the fox farm suggested feeding schedule when feeding. I haven't used any calmag at all during my grow. Could this be the reason my leaves are getting hurt like this? Thanks!

 

[Growingasmile]

I am experiencing some of this on my leaves as well, but I thought it was burning from my lights. I had my plants at 18 inches and I noticed some damage happening, rustic like on the edges, and bigger rust like marks on the leafs. I'll post pictures below. I brought the plants to a height of 24inches and didn't notice a difference. I brought them down to 30 inches and I've noticed it not happening as much.

That being said, I am also growing in FoxFarm Ocean Forest, but I have only been using Fox Farm Big Bloom, Big Grow, and Tiger Bloom with the fox farm suggested feeding schedule when feeding. I haven't used any calmag at all during my grow. Could this be the reason my leaves are getting hurt like this? Thanks!

Kind of looks like a fungus to me

 

[DramaMonkey1]

Kind of looks like a fungus to me

You got me freaking out over here . I did some research on fungi and cannabis plants, and none of the “common” fungi issues seem to match what I’m experiencing. The main thing that makes me believe it isn’t fungi related is because these leaves got these marks 2 weeks ago, and it hasn’t happened to any new leaves, as far as I can tell

 

[Growingasmile]

You got me freaking out over here . I did some research on fungi and cannabis plants, and none of the “common” fungi issues seem to match what I’m experiencing. The main thing that makes me believe it isn’t fungi related is because these leaves got these marks 2 weeks ago, and it hasn’t happened to any new leaves, as far as I can tell

Then you're probably in the clear, just keep an eye out for it spreading.

 

[DramaMonkey1]

Then you're probably in the clear, just keep an eye out for it spreading.

I’ve been thinking a lot about it, and since the plants are in light I went to check some more, and I think it could be rust mildew. I took some more pics. I don’t think it’s spreading, because I treat the plants with neem oil (organicide) once a week. But I think those leaves could be damaged by it. The first 5 days of flower were very humid because I didn’t have a dehumidifier and it stayed at about 67% humidity, but I had a lot of air flow. That being said, it is when it first showed up. Should I remove the leaves, even though it’s in flower and might not be mildew?

 

[Growingasmile]

I’ve been thinking a lot about it, and since the plants are in light I went to check some more, and I think it could be rust mildew. I took some more pics. I don’t think it’s spreading, because I treat the plants with neem oil (organicide) once a week. But I think those leaves could be damaged by it. The first 5 days of flower were very humid because I didn’t have a dehumidifier and it stayed at about 67% humidity, but I had a lot of air flow. That being said, it is when it first showed up. Should I remove the leaves, even though it’s in flower and might not be mildew?

That's a really tough question if you do don't remove them all at once stress is really bad in flower but just keep in mind if it's a fungus and it spreads to your buds you DO NOT want to smoke spore of the fungus so it can render your product non consumable if it so happens to spread.. many people once they have confirmed it's fungus called it a wipe and killed their plants to sanitize their rooms with bleach, but the issue with this is if you're pulling air from outside with no filter you're like getting your contamination from here and not previous grows or just growing conditions in general.. fungus does not like cleanliness remove all dead leaf matter and soil from your grow room floor