What is wrong? Brown spots, lime leaves

Can anyone help me with my plant?

First time grower, jack herer autoflower, today is week 5 from germination just entering into flower, today I noticed these brown spots on my leaves and they are starting to turn light green. Humidity and temp are perfect, it’s a soil grow, I have been using 2ml cal/mag, 2ml micro and 4ml grow nutes/gallon every couple days. 2 days ago I noticed some burnt tips so I stopped the nutes and just used ph water, my run off was measuring down mid 5s so I suspected lock out. I have just flushed the plant and got run off to about 6.1 do I need to increase this more? Is my plant in lock out? Don’t want her to die she has been perfect until now. Any help will be awesome!

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How about a bit more information. Fill this out and be as detailed as possible. Lights (WHAT lights), soil (WHAT soil), water (WHAT water) etc.

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:


If you were in the 5’s for ph lock out is likely the problem. Try to get your ph ranging 6.2 to 6.8. At 6.1 your at is a good starting point. Water at maybe 6.5 to 6.6 to get you ph up a little.


Thanks for the reply; some more information:

Seeds: Jack Herer autoflower from ILGM
Soil is a seed & cutting germination mix, I’ll attach a pic below
Vessels: 25cm plastic pots (?7-10L)
PH 6.8-7.0 going in, run off was PH 5.5 (please note that I have since flushed both pots with about 30L each PH of 6.9 to try raise the ph, still run off is only nudging PH 6.05-6.1)
PPM/TDS I do not have a reader so cannot answer sorry
Indoor grow
450W led light (180W power, model number GL-NM-3T-450)
Temp range 70-79°F
Humidity RH 42-62
Carbon filter with 4inch inline ventilation fan speed control with separate 4 inch inline intake fan.
Have just added dehumidifier as entering into flower
No co2
Am currently at day 36 after placing seeds into water for germination.

Hope this helps. As I’ve mentioned I’ve given both plants a good flush with pH water around 6.9 and can only get the ph in run off to about 6.1 max. I’ve actually tried last night and this morning with the same result, even with 30L running through each pot.

Feeding I have been using general hydroponics micro and bloom nutrients with professors nutrients go green cal/mag see pic.

I have been feeding about every 2 -3 days when the soil is dry giving about 2ml cal/mag, 2ml micro and 4ml bloom in 5L water (divided between both plants) ph’d to about 6.8.

Beginning of last week I upped nutrients to 3ml micro and 6ml bloom keeping cal/mag at 2ml. Noticed faint burnt tips on a number of leaves on both plants. So next feed was just pH water 2 days after last nutrient feed, then yesterday (2 days after water) I noticed the rusty spots on a number of leaves, however these are only on one plant at the moment.

It is my first attempt at growing and was really enjoying it but am stumped at what to do to fix this issue. Any help would be great.

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Well I believe nutrient burn is going on so first discontinue nutes and just cal mag for a couple of weeks. Watch new growth for improvement. PH is acceptable IMO.



I absolutely agree

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Ok thanks guys for the help, I will give that a go, just feed with water and cal/mag.

Should I try do anything with the ph? I.e Keep it higher like 6.9 as the run off is still coming out low? What ph do you recommend I feed her with?

I really appreciate the help you guys are giving, it is really reassuring to us novice growers!


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Low solids liquid doesn’t really have the strength to ‘move’ the PH in your media. You can cheat on the high side but don’t exceed peak (like 6.8 in soil). I tend to PH a bit lower for all of my stuff and they seem to be fine. You will find your sweet spot for your space.

Grab a tds meter - very cheap (like 20$ on amazon) just so you have an idea. And make sure you get the soil chart for gh series (they have it online) - I was using what was on the bottle which is incorrect for soil

Ok so I have stopped the nutes and just giving water PH 6.8 with cal/mag. I gave 4ml for 5L (bottle suggested 1ml/L) so I gave just a bit less. I’m noticing today that my newest leaves are starting to droop and curl under, no rust spots on these leaves but they are droopy as hell. See pics. I tested my run off and it was back down to 5.9 even with 6.8 going in. And this is after a big flush a couple days before.

If you have any other suggestions even if it’s just stick with the plain ph’d water for a while id love to hear it @Myfriendis410 @Sirsmokesalot @Hogmaster @shindig153 just want to make sure I’m still heading in the right direction. My second plant which had far less rust spots seems to be doing fine with no perceivable issues despite being same strain and under same conditions.

Cheers guys


If you took the pictures just after lights on then the plants have not changed their ‘sleep’ posture. If more than an hour from lights on or off, responding to watering.

Keep with that regimen for a couple of weeks and lets see how they look then. If anything else comes up of course tag me.


I got a tds reader as suggested to check my ppms. My sick plant is stretching in 2nd week flower but there are a lot of discolored and spotted leaves all over. New growth so far is ok but the rest of the plant not so much. I have just fed ph’d water as suggested with some cal mag this week and have just used my new tds reader. My ppm goin in was 117 and coming out about 150, is it safe to say my nutrient burn issue is resolved and I can start giving her some nutes again?

There are quite a few yellow lower leaves maybe 6 or so, I’m concerned she might now be deficient in nutes with a ppm run off at 150? Should I slowly increase her GH trio nute feed? I’ve read mixed info on ppms for soil with autoflowers some say not to exceed 500-600? Should I slowly increase to those levels over the next couple feeds? @Myfriendis410

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Your runoff is telling you that the media is pretty well exhausted (great use for a TDS meter). For autos that feed heavily with that media I would like to be more around 800 ppm.

You should resume your feeding schedule immediately IMO.

Another question before my next feed, I top dressed 4-5 tsp of garden lime (powdered) to both my plants to help stabalize the soil ph (as my runoff was ph5.8 with 6.5 going in)
Final run off was 6.4 after ph watering it in with ph 6.4 so I was happy about that. Ppm in runoff was 230. This evening (24 hours later) I’ve noticed what looks like nute burn on a lot of leaves (burnt tips curling up) I don’t know if this is just a coincidence in timing with my already damaged leaf tips which have dried and curled up or if raising my soil ph as allowed my plant to suck up a lot of locked out nutrients over night? As I mentioned ppm after adding lime was only low 200s is it even possible to get nute burn with runoff ppm that low? My tap water ppm is 78 to begin with. Most burnt curled tips are on the already damaged leaves however when I closely look at the newest leaves there is what looks like the tiniest bit of burn. I will check again in the morning when I wake to see if they are worse.

I was planning on feeding tomorrow night GH trio with ppm up to 400-500 but seeing a number of curled burnt tips has me so confused…? Any suggestion @Myfriendis410? :pray:

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How about a picture?

Your plants are starving, based on the TDS reading of your meter. Leaves damaged previously will not recover. Look to new growth for improvement.

Ok @Myfriendis410 , so today I just hit week 8 and am having even more problems. I have been flowering for probably about 5 weeks now. Pistils are all white still, and I have clear trichomes some cloudy so not quite ready for harvest I’m guess a couple weeks still needed but problem is all leaves are starting to go yellow I know this happens normally but in addition I have burnt brown curled tips on almost every leaf. I’m getting signals of both nute burn and deficiency at the same time and I don’t know what to do!

I gave my GH feed 9 and 6 days ago with ppm of about 500 and shortly after I noticed brown tips starting to form on new leaves which curled and went crispy. This progressed so my next feed I gave PH’d filtered/Distilled water 50:50 only. Ppm in 35, run off down to 350 on my worst affected plant and 200 on my lesser affected plant. I think I may have a very nute sensitive plant? I have brown tips and splotchy marks on some of the newest leaves in the buds too, see pics.

My question is, can I be burning my plants with ppm so low? Or is she starving? I don’t know whether to feed them or just use water. I worry the plant will run it’s life cycle before the buds have matured.

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The problem you are experiencing is the progression of damage already taken by the plant. You have to look to new growth for improvement. Assuming good drainage and watering practices it would be prudent to be in that 800 ppm range with PH’d nutrients. You may want a bit of N (something I’ve been doing) to maintain leaf vigor through flower. You probably have another 4 weeks of flower so do need to support the plant during that time.

Ok thank a lot, some of my newest leaves have what look like burnt tips too even some sugar leaves have brown splotches but my ppm run off is well below 800 so I will give more feeding a go, ph is now good at about 6.2 run off and it’s going in at 6.4 so and I’m getting about 15-20% run off, watering every 3 days once pots are light so hopefully the food will help, just was unsure with some of the newest leaves showing the same brown marks and tips as older ones

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You could do a couple of other things like add some Mycorrhizai or other fungal soil treatments. Earthworms added to your soil can help aerate etc. Try to get your root zone happy.