Weird spots on fan leaves

So in the last few days I have noticed these spots showing up on my fan leaves and I can’t seem to figure it out. It’s only on the one strain that I have growing and I have 3 different strains all taking the same type of nutes and water etc… the only issue I have ran into during this entire grow. It’s been smooth sailing so far and I’ve been enjoying the hell out it! First time grower and I chose some hard strains to start with: Chemdawg, LSD, & Green Crack. The only strain I’m having difficulty with right now is the Chemdawg. Right now I’m sitting at Day 60 since germination and Day 25 since I started force flowering.

  • What strain: Chemdawg Feminized from ILGM
  • Method: Fox Farm Ocean Forrest with perlite mixed in
  • Vessels: 4 gal plastic pots from Lowe’s
  • PH of Water: I always keep the water going in between 5.9-6.1 as far as the run off I have not checked it.
  • PPM/TDS or EC of nutrient solution: I have been using half strength nutes from fox farm. I have been mixing big bloom and buds&bloom together one at a time at half strength and my TDS is usually around 1163 and my EC is usually 2313. I think I need to use 1/4 strength nutes mixed together instead of half strength.
  • Indoor or Outdoor: indoor controlled grow in a 4x3x7 grow tent.
  • Light system: 2 - Mars Hydro TS600w LED
  • Temps; Day - approximately 75-79, Night - approximately 65-69
  • Humidity; Day - 60-65%, Night - 50-55%
  • Ventilation system; Yes. Vivosun 6 inch 390 CFM Inline fan
  • AC, Humidifier? No. De-humidifier? No.
  • Co2; No

What is your growing medium?
How far along?
Any bugs or insects seen?


I have answered all your questions except the bugs in my full length post but I’ll answer them again.

I’m growing in (3) 4-gallon pots and it’s a mixture of Fox Farms Ocean Forrest soil and perlite.

Right now I’m at Day 60 since germination and Day 25 since force flower.

There are no bugs that I have seen. And I have looked up and down left and right and all over. Twice. I haven’t noticed anything as far as a bug or insect.

have you given any of your plants a Cal/Mag feeding at all during the grow?

(I was on my phone so I couldn’t see your list above)

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Looks like magnesium deficiency. You are at the point in the grow that any calcium and magnesium deficiencies show up. Using cal-mag once they start flowering can keep them looking healthy.

Once the deficiency shows up it’s much harder to correct and get the leaves back on track. They tend to continue the decline. Start using cal-mag with every watering or feeding, even if it means cutting back on other nutrients to maintain target ppm. After a few weeks you can go back to full strength feeding and only use cal-mag on the water days.


It’s all good bud my bad lol but no I haven’t actually used that yet. But it looks as tho that’s what some people are say it is as well… so off to the store I go!

Awesome information bud! I appreciate it. This is my first grow so I’m learning still. But I have read up a little on cal-mag and that’s what I’m hearing too. Thanks for the advice, off to the store I go.