Organic Grow Flowering - Rust Spots. Is this a cal\mag deficiency?

[ELGenerali]

I'm almost to my 7th week of this grow and my plants are in the flowering stage. I started to notice the some of the fan leaves are getting these "rust spots". From all my research I think I am dealing with a cal\mag deficiency. FYI, I am doing an all organic grow. Details of my grow are below.

Not sure if it matters or not, but around week 4 I dealt with and fixed a high nitrogen issue. I noticed the leaves were dark green, clawing, and the plants had kind of stopped growing rapidly. So I fixed this by flushing the plants a couple of times. Wondering if when I flushed the soil I leached away too many nutrients. Since the flush I have added more "Earth Dust Boost".

Soil = Root Organics Lush
Soil Amendments = Earth Dust(pre grow, soil baked for 2 weeks). Earth dust boost about 4 weeks into the grow, right before flowering.
Lights = SP3000 LED. (Hanging roughly 24"-26" above canopy
Pots = AirPots


So, just curious if I am on the right track with the cal\mag deficiency? Debating on making a Earth Dust nutrient tea, and hopefully this will resolve.

 

[ComfortablyNumb]

It does look like Cal-Mag. The real question is why? Did you add any recharge?

 

[ELGenerali]

As a matter of fact I did. I added recharge on 2/26. That was 9 days ago and per the instructions, you should only add it every 7-10 days. Below is the "recharge" I used.

 

[ELGenerali]

I've also done one top down dress of Earth Dust Boost.

 

[ComfortablyNumb]

Instructions... ummm Yeah. Ok.

Next time, add a tablespoon of Recharge to the LUSH along with the BASE and BOOST before cooking for 2 weeks. Mix the crazy out of it, then cook it.
This is why you are having cal/mag issues. You should also add a half dose of Fish Shit before cooking. Good stuff. Once all that cooks, those millions of MBE's are going to multiply like rabbits and your soil will be able to grow a redwood. Well... some really juicy weed anyway.

Fish Sh!T

Homepage - Fish Head Farms

fishheadfarms.com

Mix a 1/4 teaspoon of epsom salt in filtered water and water the plants.

 

[ELGenerali]

Cool, I was actually following one of your posts and thought the Fish Shit was only used during flowering. Next time I will def add some before I let it cook for 2 weeks. Thanks for the advice!

I was planning on giving the plants a nutrient tea I made from the BOOST. Should I wait on that, since I need to give epsom salt, or do you think it matters?

 

[Bluntsmoke]

Looks like a pk deficiency to me

 

[ComfortablyNumb]

No, skip the boost for now and just the Epsom. Be careful, not too much. Let's see what it looks like 24 hrs after the Epsom.

 

[AlfaDog]

No, skip the boost for now and just the Epsom. Be careful, not too much. Let's see what it looks like 24 hrs after the Epsom.

Why magnesium sulfate it's symptoms are calcium deficiency

 

[ComfortablyNumb]

It has more than one which says pH.

 

[Highcountryfarms]

If you have Epsom salts now Is the time, that will give you the mag/sulfate boost. In unclorinated water dissolve your Epsom and a powdered eggs shell. 1 tbsp molasses, Hit it with compost and ewc if you got it let brew for 24 hrs or so and drench soil.

 

[Shaded_One]

Common Deficiencies in Cannabis - Plant Medicine Mama

Deficiencies in Cannabis Are All Too Common. Let Me Help You Identify and Fix the Deficiencies You May Be Experiencing.

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[Perception]

To me, it looks like nutrient lockout from salt buildup and/or a PH imbalance. Flushing could reduce the negative impacts of either, but being so close to harvest, you might just want to leave it. I've have similar problems happen from adding too many nutrients mid flower. Less can be more.

Watering technique can have a impact on these problems happening too. I like to make sure that I water-to-runoff about once a week (if you are in pots).

I bet that checking the PH and PPM of your runoff may give you some clues. Good luck.