Brown spots on some leaves (first grow)


New Member
Jan 17, 2021
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Hey guys !

I started my first grow a month ago, and everything seems mostly fine for now.

Here's a pic of the babies, I think they seem pretty healthy... ? The 2 on the left are Runtz, and the 2 on the right are Crystal White.
The smaller one is a week younger, one of my seeds didn't sprout and I had to start an other one.


First question : should I be worried about those curly leaves on the smaller one ?


Second question : since a week or so, I noticed brown dry spots on some leaves (see pics below), 2 mostly, but it started on 3/4 others too.

Any ideas on what it could be caused by ? From my internet researches, it seems it could be related to a fungal infection ?



Some additionnal informations :
- I'm using BioBizz starter pack as fertilizers, and I'm following the calendar they give for quantities.
- They're under a LED full spectrum light, a MarsHydro TSW2000.
- Pots are 18L, and I'm watering with 1.5 to 3 liters of water / pot every 2-3 days.

Feel free to ask any futher informations required, and thanks for your help !! :)


One Toke Over The Line
Staff member
Jan 18, 2020
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Here, been banned everywhere else
Firs of all you have some work to do my friend. Never let leaves touch your medium. Prune those leaves off. Probably could prune the whole plant a bit.

Nest, brown spots could be spider mites. Check under the leaves and look close.


Nitrogen Toxicity
Example of a cannabis plant with a nitrogen toxicity (dark green leaves with the tips turned down)

Problem: Dark green leaves, shiny leaves, clawing, weak stems, and overall slow growth. Marijuana leaves that are nitrogen toxic often get “The Claw” or talon-like leaves that are bent at the ends. They also do an odd curving (or cupping) that is often mistaken for overwatering, but is unique to nitrogen toxicity. You can see a “clawing” leaf in the pictures below (click each picture for a close-up).
Leaves that turn into claws often start turning yellow and dying if the nitrogen toxicity is not treated, much like a nitrogen deficiency, only the leaves will continue to get more and more clawed. Leaves eventually turn yellow or brown and fall off. You can tell if yellowing is caused by too much nitrogen because the rest of the plant will be dark green, and the yellowing leaves will turn into claws first.
The majority of times that growers encounter problems with nitrogen, it’s from giving too much of it to their plants.

Could be something else as well. Over watering possibly. However the leaves don't look dark green which is a classic sign of over watering. Somebody else might have other ideas as well.