Brown spots on lower leaves

My pretty plants are starting to not look so pretty. I treated for possible fungus gnats 3 days ago. The neem oil left a white film on the leaves, not sure what is up with that? Anyways, I now have brown spots on the leaves that weren’t there, at least I don’t think so since irs Thanksgiving and I’ve been cooking all day. I set sticky traps 2 days ago and have only found one bug so not sure if I had a big problem with them or not. Does anyone know what this is?




Too me it looks like a magnesium deficiency. If you could give a little more info on your grow we will be able to offer some help. Like what is your medium, nutes, water, are you ph balancing before watering/feeding? Are you using calmag?

I definitely think that this could be a nute/ph issue. Sorry I forgot to give all the deets:

Banana kush autos, 27 days old
1/2 cheap potting soil, 1/2 FFOF (I know I made a mistake with this)
I’ve got 2 blurples and a Mars Hydro tsw 200fabric pots

I’ve been lightly giving fox farm trio, not tiger bloom yet and just started cal mag. I just got a ph and tds meter along with ph up and down and they had their first correctly ph’d feeding to 6.5 ph last night with the nutes I mentioned above. They looked ok this morning but with all hustle of Thanksgiving I wasn’t able to fully assess them until now. Could this be stress from ph fluctuations? I gave a flush with ph’d water only just now and said a prayer.

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Just keep giving calmag with your waterings and feedings. Next time you feed or water, do it until you get some run off and measure the ph and tds of the run off. The calmag should get you back on track, but keep an eye for the condition incase it worsens. The affected spots will never heal, but as long as is stops spreading you’ll be good.

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I don’t quite understand what I’m looking for with the runoff ppm and ph. What should I be looking for with that? My ppm was 750 and ph 6.5 last night before feeding but I failed to check the runoff.

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To make sure your ph isn’t crazy and your tds isn’t crazy. I assume since you just got your meters that nothing was ph’d previously. Just want to make sure nothing is getting out of whack that’s gonna sneak up on you later. If you want after you get some runoff numbers feel free to tag me and I will help you out. I’m not trying to scare you or anything as your girl looks healthy except for the small mag deficiency. Sometimes it can take a little while for a problem to show up if there is one. Just trying to be proactive for you is all. The calmag will most likely fix your issue and you’re all good. No need to stress :slight_smile:

Thank you so much! I am kicking myself for being so impatient and not learning more before dropping seeds but this is how we learn.

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And yes, I wasn’t getting ph/ppm readings until now unfortunately

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Yeah don’t stress it. Honestly having things go wrong or some hiccups along the way is the best way to learn. You get to have first hand experience with issues so when you spot them in the future its easier to diagnose and correct :slight_smile: feel free to tag me whenever and I will help. If I can’t help I can definitely find someone and tag them for assistance.

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@ReelOfishal so no new spots today! They perked up a ton since I did the ph’d water flush last night but the leaves seem folded a little. I’ll take more pics shortly, my dogs were doing the potty dance and I only got the one pic. Lol

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Usually the leaves curled up like that or “tacoing” with the serrated tips pointing up on the leaves is a sign of heat stress. What’s your temps like today and how close and what power are your lights on? It doesn’t look bad though just slightly to me.

Lights are 18 inches above, I just raise them yesterday because they did shoot up quick and the brown spots I thought were from it at first. I just took a few pics. I don’t believe there are any new leaves with brown still.




Lights were at 16 inches yesterday but I’ve been trying to keep them at 18. The mars hydro is on 60%.

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The brown spots can be caused/accelerated from too high of light intensity because its causing the plant to consume more nutrients at a faster rate. So when it runs out of nutrient supply in your medium it starts eating it from its own leaves.

Would it normally be the upper leaves closer to the light if it was heat burn? It’s the lower to middle leaves that are affected.

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Not necessarily “heat burn”, but the light intensity caused the plant to eat up its supply of magnesium at a faster rate than you were supplying it.

Oh that’s interesting, I hadn’t thought about. I wasn’t planning watering until at least tomorrow since I watered last night but that was only water. Should I only feed calmag tomorrow? I don’t even know what I’m doing anymore it seems.

Should I remove any leaves or nah?

I would just leave the leaves for now. I wouldn’t water/fed them until the pots are light. Cannabis likes a wet/dry cycle and if you over water them they will get mad at you. There is a difference between over watering and giving them lots of water. Example if the plant was dry and ready for water you could give it 5 gallons of phd water with no harm, but let’s say you watered it with a gallon and 2 days later did it again before it was dry that’s what hurts it and is considered over water. Over watering isn’t related to the amount of water it’s related to the frequency.

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