Leaves issues, brown spots/necrosis

Hello everyone, this is my first post and I hope I’m doing it right. Long story short, I’m having some issues with my plant and I could use some help, I’ll try to give as many details as I can.

Problem: Yellow/brown spots on leaves and leaves’ tips curling downwards

Medium/grow method: soil (BioBizz light mix)

Feed and supplements used: currently using BioGrow and BioBloom, planning on adding TopMax later in flowering

water source: tap water

Strain/age: RQS Quick One, 35 days old

light used: sunlight, usually 11-12 hours of direct light

Climate: temps hover between 28C/82F and 30C/86F, but can go to up to 32C/90F between 12:00 PM and 2:00 PM. At night temps are between 18C/64F and 20C/68F. RH is always at 50-70% but can go up to 90ish based on the weather.

Additional info: The plant is growing outdoors. I’ve been careful not to overwater and/or overfeed (I’m giving her half the suggested ferts) especially considering how hot the climate can be during the day. Yellow and brown spots started 3-4 days ago whereas the curling appeared a couple days ago. Some upper leaves are also curling inward.

I’m also posting some pictures. The first, second and third pictures were taken 3 days ago, whereas the last 2 were taken today and show two of the biggest fan leaves I had to remove today. Thanks in advance!

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Check this out.

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@Hellraiser, hoe you don’t mind me tagging you, can you help him out

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It doesn’t really look like a Mag deficiency. There is no yellowing, everything is a dark brown and spots started to appear away from the edge of the leaves. Lighting in the pictures probably isn’t the best, but the spots are darker than that.

I forgot to add that the leaves feel papery at the touch.

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What water are you using? RO, filtered or straight tap water? Monitoring PH?

Using tap water, ph of the feeding solution is 6.7. Haven’t checked runoff ph yet, might do it tomorrow.

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Are you allowing the water to sit over night to let the chlorine gas off?

I’m still new to this but I see signs of heat stress on a few of those leaves.

If it was me, I’d keep them in a shady area for a few days and bump up the nutes a little. The leaves should be a bit darker at this point. To me, they look a little hungry.

I have never done that because I have never felt the need to. I’ve never had this kind of problems with other strains. Does it actually make a difference?

Yes, she’s definitely showing some heat stress :\ however there is not much I can do considering she’s growing outside. I’m trying to move her to shade during the hottest hours and she’s slowly recovering, higher leaves are completely unaffected now and she’s still growing well, thankfully.

As for the brown spots, I suspect it might be a Potassium deficiency. I’ll try to up bloom nutes a little bit to see how she reacts.


Yeah, that’s about all you can do at the moment. They are very hardy plants and can take quite the beating before they start dying. Your plant looks good so I wouldn’t stress.

Bump up the nutes, along with some shade, and she’ll do great! Just remember, you’ll still need some Nitrogen in your mix, not just bloom nutes.

Happy growing! :+1: