Nutrient burn? Nitrogen toxicity?

• Indoor or outdoor? - size of grow? Indoor 90x90x185 cm

• Origin of seeds? White Label Super Skunk

• Regular, feminized, or autoflower? Feminized

• Origin of water. PH, EC/TDS of source water? Tap PH ~6.1-6.6 after adjustment, don´t know the rest

• PH and TDS/EC of if mixed solution? ~6.1-6.6

• Grow method? Soil, Soil-less, Coco, Hydro, Aquaponics. Please explain. BioBizz Light Mix Soil

• Nutrients or fertilizer system used. BioBizz: Root Juice, Bio Bloom, Bio Heaven

• What type of lighting are you using? LED, HID (MH, CMH, HPS), or Fluorescents? Please elaborate. Lumatek ATS200W Pro LED

• What are the temps in your growspce? Day / Night? ~24°C / ~20°C

• What is the RH = relative humidity in your growspace? Day / Night? ~65% / ~60%

• AC, Humidifier, De-humidifier? none

• Do you have a Ventilation system? Size? 4", 6"? 4“ Exhaust Fan with carbon filter, passive intake and a small oscillating fan

• Co2 Yes / No? No

• How long have you been growing? 31 days since sprout

Hey guys,

Very first grow. second post here since I ran into some issues during seedling stage.

I transplanted after two weeks of growth into prefertilized soil but the next watering i added some nutes. According to the manufacturer (same company for soil/fertilizer) that was recommended.
But now all 3 got clawed tips. Some of them are light green some start to be slightly brown. Did some research and it would indicate nitrogen excess. Doesnt seem to be severe though.

But i also noticed some irregular brown spots. Are those nute related too? The front right one has some general light green disoloration at the canopy as well.

The new growth from the one in the back are also canoeing and twisting when they get bigger. I first thought light stress but i stopped adjusting the light (currently at 50% and 40cm to canopy) to see what happens and every new growth regained the normal shape after a day. Could there be another reason than light?

I’m also not too freaked out because they overall look happy and healthy. And they are growing like crazy.
Just want to know if my guesses are correct. And if i have too do smth (besides cutting back the nutes of course) or just wait it out.

Any advice is appreciated!
Cheers Zero


That appears TO ME to be a very light nitrogen toxicity. Not a huge deal, very common as I’ve had it happen at some point with ALL plants grown with liquid nutrients.


I think you look good. Many growers want the tips to be slightly burnt…pushing the plant hard. If would stay the course.


We have very soft tap water here and I have to bump my calcium when I use certain nutes :metal:t2::green_heart:


Those plants are good to go. Stay the course.


If the buds bud, you’ll get stoned. Nutrients added do not make weed stronger, they just make bigger buds.

Hey @Riskguy @SlayinAsquirter @StonedCold13 @Mothman , quick update: more fan leaves are starting to look like the second picture from my initial post or showing some weaker form of it (especially the big ones). The marks also appear in the middle of the leaf and not on the tips or edges so much. Can that happen with nutrient burn?

I also looked up other causes and the pics i found for Calcium deficiency matched pretty well.

The light was also very close since i was gone over the weekend and they grew. I measured the distance for the light again and they were at about 20-25 cm instead of 40. Maybe its some light burn?

Here are some photos:

Thanks in advance for your replies!
Cheers Zero


White tips in 1 for sure light, but good like people said. Light = photosynthesis = happy plant.

Pic 2, maybe burnt end on leaf. Can’t tell. Too much ligh if so…

In middle of leaf…
The trouble you’ll find is that leaves are green, yellow, or brown with limited other information for a lot of things. Your left to deduct from your own work.

Check your nutrients and are you using calmag or similar?


Ok…it does look like you have something going on. You transplanted 4 or 5 weeks ago into a soil with fertilizer…it is likely depleted now. When I look at what you are feeding it looks like you are feeding Bio-bloom…appropriate if there is nitrogen in the soil. Now that you have likely used that up, I am thinking you should be using Bio-grow until they go into flower.

I admit I am not great at deficiencies… @MidwestGuy is a good resource and always willing to help too.

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Like all things weed…it depends. There are a few super soils out there that claim to get you all the way to harvest. Most of the popular soils for growing have a 3/4 week supply of nutrients in them and then the plants will need something to continue strong growth.

All that said - the quality and yield will suffer if you do not provide the plant with the building blocks to keep growing and producing flowers.

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@AVeryScaryGhost not using CalMag yet but i’m going to get some and try it. I had trouble with higher temperatures for a time and read that they get CalMag deficiencies cause they transpire way more than they take up.
On that note the leaves feel kinda dry for me, but then again its my first grow and i dont know what they are supposed to feel like :smiley: how do i check my nutrients?

@Riskguy i’ve transplanted on the 22.06 so a little more than two weeks ago, and the soil is said to have nutrients for 4 weeks, i gave water for transplant and the next watering gave 50% of the recommended dose of fertilizer.
Like i said the comp is the same for fert and soil and they recommend to feed when the plant is 10-15 cm or 2-4 leaves even in the prefertilized soil so maybe it is indeed a deficiency and not nute burn idk…
Might add that the majority of browning is on the plant that has the most growth by far because it grows the same rate as the others but has two ‘main’ stems with bushy foliage:

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Thanks, that makes sense

@Riskguy @AVeryScaryGhost @SlayinAsquirter @StonedCold13 @Mothman @MidwestGuy

So just to dial back in, one more big fan leave on another plant got the same patches. And some others got lonely spots. I did a lot of research amd I’m starting to think its a deficiency problem and not nitrogen toxicity. Since the one most affected had no clawing and all of them are missing the dark green color and starting to become light green. The clawing could be due to little space, they are growing against the wall in my 3x3.
So my plan is to feed again tomorrow and see what happens.

Do you think im ‘in the green’ with my plan?
Some advice or thoughts? Should i start lower than the 100% dosage?



@sklxzero I will admit that I have not had much experience with deficiencies.

Here is my two cents for what it is worth. I do think that overcrowding is causing some issues with leaves that are covered with other leaves and hampering good air flow. In my tent I have an additional fan blowing below the canopy to keep air moving. It is normal for lower leaves to fade.

IMO you should feed at 50% strength of Bloom nutes since the soil still has nitrogen every other time you water. In a week or two move to full strength Grow nutes.

Others…feel free to amend the advice

Nitrogen deficiency and nutrient lock-out are similar and I’ve mistaken one for the other in the past. I’d recommend checking your soil ph because if it’s too high or too low, the roots won’t be able to uptake nutrients. If the soil is off, flush them with neutral water (ph7) and then give them some micro nutrient solution and an all purpose such as Fox farm Big Bloom. Remember to test your soil / run off often to be able to catch these problem before they become issues.

@Mothman i watered till runoff and the ph was 6.7 6.6 and 6.5. And the one most affected by the browning had the lowest ph. The browning also seemed to stop or at least dont affect new leaves/growth.

They seem a little bit droopy now but i had to water a lot to get some runoff

So i guess its not nutrient lockout and i will follow @Riskguy suggestion

Thanks a lot for the advice guys!

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