Brown spots, not from watering or anything

I’ve never seen this before. Can’t see any pests but idk… I have not sprayed them so it can’t be from that. Right now two plants have this.

I did buy a pest spray called garden safe insecticidal soap. If these are pests how should I apply? Will the lights make the soap “burn”?

Looks more like a nutrient deficiency. Cal-Mag or phosphorous. @Cannabian @Covertgrower @Myfriendis410 can you help.


I would have to say nute burn and calcium (likely a def). It would be helpful to know more.

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)

  • What strain, Seed bank, or bag seed
  • Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
  • Vessels: Pots, Grow beds, Buckets, Troths
  • PH of Water, Solution, runoff (if Applicable)
  • PPM/TDS or EC of nutrient solution if applicable
  • Indoor or Outdoor
  • Light system
  • Temps; Day, Night
  • Humidity; Day, Night
  • Ventilation system; Yes, No, Size
  • AC, Humidifier, De-humidifier,
  • Co2; Yes, No

Always try to upload a clear picture of any issues you may have to allow the community to assist you.

Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner :slight_smile:



I would concur with @Myfriendis410 , but youbshpuld fill out a support ticket, we can get a better picture of the environment.


Green gelato auto. Soil is pro mix. Small amount of ff bloom nutes, no exact number but I’m only feeding maybe once a week as directed. Watering when soil droughts with tap water. Indoor but started outdoor and I have caught myself bringing little white nymphs in, Mars ts600 12" away. 12/12 cycle. Day temp is 80 or so. Humidity around 50. No night readings yet. Last runoff gave ph of 6.4 and unregistered on tds meter which was weird. Soil DID go completely dry that time and I brought them back with water with ff bloom nutes and organic Epsom.

Thanks guys @Cannabian @Deepsix @Myfriendis410

Just to mention, I see the same thing on the bag seed plant. It was started with MG and raised differently. The only thing these have in common besides sharing the flower space is being in contact with outdoor plants. I’m about to leave for the weekend and I’m thinking about trying that insecticidal soap but I don’t want it to ruin the buds taste or burn the plants more. Heavy flush and hope for the best? If I flushed them like that I would put them outside to drain and they would be in a sun light cycle and super high temps and humidity… Your experience is appreciated

Won’t work on a flowering plant. If you want to treat, use Captain Jack’s Deadbug Brew or Safer Caterpillar Killer (Spinosad or BtK respectively). Peroxide and water misted on before lights out will work too.


Ok. Are you leaning towards a pest or nute problem? Ill be gone before lights out. Is it best to flush and leave outside or leave and spray with dilute peroxide when I get back?

The products take five days to work. Peroxide is instantaneous but dissipates into water and O within minutes.

1 Like