Rusty spots on my leaves

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SmileyBigs

Member
Having some issues with my AutoFlower GG4 strain . The leaves looks to as if they are rusting and she is 50 days old as of today . Thought it could be a cal-deficiency or even nutrients burn , I have tried to flush with still the same results . If anyone could help anything helps thanks .
 

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Red Hard Head

Well-Known Member
No bugs on underside of leaves? Looks like potassium and calcium deficiency. The buds should be much bigger, some thing is holding growth back.
 
calvin.m16

calvin.m16

Well-Known Member
Looks like Calcium deficiency or Iron toxicity. What are you growing them in? Adding any nutrients or additives? What kinda water are you using? Tap, RO?

I recently watered in full strength TM-7 which is a micronutrient pack and had some plants show Iron Toxicity signs. Healthy leaves other than weird little rust spots, it only happened after I fed the micronutrients so it had to be toxicity.
 
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SmileyBigs

Member
Red Hard Head said:
No bugs on underside of leaves? Looks like potassium and calcium deficiency. The buds should be much bigger, some thing is holding growth back.
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No bugs , I have put a magnifier to them to see . Nutrition I’m running the fox farms trio. -Big bloom 4:1 Tiger Bloom 3:1. Teaspoons to Gallon Ph : 6.5
 
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SmileyBigs

Member
calvin.m16 said:
Looks like Calcium deficiency or Iron toxicity. What are you growing them in? Adding any nutrients or additives? What kinda water are you using? Tap, RO?

I recently watered in full strength TM-7 which is a micronutrient pack and had some plants show Iron Toxicity signs. Healthy leaves other than weird little rust spots, it only happened after I fed the micronutrients so it had to be toxicity.
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I have tried the fox farms cal-mag but still same results
 
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Red Hard Head

Well-Known Member
Those buds should be bigger. If worried about excess nutes try a microbe flush. Compost or EWC extract microblif or liquid photosynthesis. No need brew a tea. And top dress some dolomite, this will help with low pH cal and mag.
If I remember fox farms has strong and weak feeding recommendations. If so try the stronger dose.
Also it's gg4 and an auto both factors combined can be finicky.
 
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SmileyBigs

Member
Red Hard Head said:
Those buds should be bigger. If worried about excess nutes try a microbe flush. Compost or EWC extract microblif or liquid photosynthesis. No need brew a tea. And top dress some dolomite, this will help with low pH cal and mag.
If I remember fox farms has strong and weak feeding recommendations. If so try the stronger dose.
Also it's gg4 and an auto both factors combined can be finicky.
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I’m thinking my ph is low at the bottom the run off was only 5.4 ? Would that cause this ????
 
calvin.m16

calvin.m16

Well-Known Member
SmileyBigs said:
I’m thinking my ph is low at the bottom the run off was only 5.4 ? Would that cause this ????
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Absolutely, you've probably had pH causing lockout.
pH levels where nutrients are locked out, and which pH below 5.0 lock out the following:
  1. Phosphorus (P)
  2. Calcium (Ca)
  3. Magnesium (Mg)
  4. Iron (Fe)
  5. Manganese (Mn)
  6. Copper (Cu)
  7. Zinc (Zn)
pH above 7.0 locks out the following:
  1. Phosphorus (P)
  2. Iron (Fe)
  3. Manganese (Mn)
  4. Zinc (Zn)
  5. Copper (Cu)
  6. Boron (B)
Manganese Deficiency, look familiar?
1678457526423.png
 
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SmileyBigs

Member
Man I can’t thank you enough for giving me this info , and yes that’s exactly what mine looks like other than the yellowing of the leaves . Question ? Will she survive or should I just start over again ? What’s the best way to raise the ph at this time into this grow or is it even possible?
 

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calvin.m16

calvin.m16

Well-Known Member
SmileyBigs said:
Man I can’t thank you enough for giving me this info , and yes that’s exactly what mine looks like other than the yellowing of the leaves . Question ? Will she survive or should I just start over again ? What’s the best way to raise the ph at this time into this grow or is it even possible?
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You can get some smoke off them, just make sure you keep an eye on PH and keep in mind runoff PH is very neglible idea of the rootzone since your measuring what is coming out of the pot vs what's left in the pot.

Say my runoff pH is 5.0 and I want my pH to be 6.0 I will feed a 7.0 solution to hit 6.0 then feed 6.0 then on unless I notice another issue. This is what I like to call the pH Dance. A quality growing medium will make this unnecessary. If your in containers and not fertigating a few times a day then its really important to have a well buffered growing medium, ProMix HP-CC seems to hold stable pH for me in 5 gal pots feeding once a day. In Coco/Perlite I am having problems with pH crashing down to low 5s and this is because it is inert medium with no dolomite lime etc to neutralize excess acid..
This is primarily an issue because I am unable to use my well water cause the poor quality so I have to use RO filtered water which has no calcium, silicates or minerals in it.

Are you feeding any nutrients that have Manganese in it? The plants usually need a pretty small amount of it.
 
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gurelybill

Member
Here are some possible causes of rust-like discoloration:

Nutrient Deficiency - The most popular cal-mag deficiency can cause rust-like spots on the leaves.
Disease or Pest - Rust fungus or spider mites can also be the cause of rust-like spots on the leaves. In this case, you need to thoroughly examine the signs of any disease or pest.
High Temperature - Environmental factors such as like high temperature, low humidity can also cause rust-like spots.
Overfeeding - Too much nutrients can cause nutrient burn and as of result it generally appears brown spots on the leaves.

To favour yourself I suggest you get in touch with an experienced grower.
 
Nutty sKunK

Nutty sKunK

Well-Known Member
I think it’s very obviously lack of calcium. Cal def is one of the easier deficiencies to diagnose. Rust spots with minimal yellowing.

Autos demand a large amount of calcium during stretch/initial budding.

I’d give or up the dose of calmag and wait for the symptoms to stop spreading. Leaves affected won’t heal. Takes 4-5 days for calcium to stop spreading in my experience.

Plant still looks ok tho! Maybe a little small but that’s most likely due to your light being low wattage.
 
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SmileyBigs

Member
Nutty sKunK said:
I think it’s very obviously lack of calcium. Cal def is one of the easier deficiencies to diagnose. Rust spots with minimal yellowing.

Autos demand a large amount of calcium during stretch/initial budding.

I’d give or up the dose of calmag and wait for the symptoms to stop spreading. Leaves affected won’t heal. Takes 4-5 days for calcium to stop spreading in my experience.

Plant still looks ok tho! Maybe a little small but that’s most likely due to your light being low wattage.
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Thanks for the info , every lil helps . What would be considered a good wattage for a 3x3x6 tent .
 
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