Burn or deficiency?

Hello. Here is some background.
White Widow Autoflower - 3gal fabric pots from seed - week 4 currently - organic dry amendments - coco - 364W LED - 2x4 tent - water pH 6.5-6.7

So, I started seeing some rust spots on the leaves of one of my girls. Friends figure it was some splash back from when I top dress amended last week, but it’s getting a little worse. On another plant, the leaves seem to be turning yellow and one looks to have a brown tip now. I figure it’s either a P or K deficiency but it could also be a nute burn, but I didn’t think slow release dry amendments caused burns. Hard to tell from examples online. Anyone seen this before in autoflowers?
Other pic is the overall from above.

1 Like

If you are in Coco I personnally would drop pH to 5.9-6.2 range. 6.5-6.7 is more suited to regular soil.
Brown on the tips might be nute burn, but in Coco you might be seeing the beginning of a calcium deficiency. Here is a pic of calcium deficiency:


It helps to have a ticket filled out


Photo or Auto?

Soil in pots?

System type?

PH of runoff or solution in reservoir?

What is strength of nutrient mix?


Light system, size?



Ventilation system;

AC, Humidifier, De-humidifier?

Answer the things that are applicable. More folks will likely weigh in.

[quote="Reticence, [/quote]

Strain? White Widow Autoflower

Photo or Auto? Auto

Soil in pots? Coco with dry amendments

System type? Unsure what you mean

PH of runoff or solution in reservoir? Not watering enough for run off.

What is strength of nutrient mix? 70/30 4-4-4/2-8-4 gaia green dry amendments

Indoor/Outdoor? Indoor

Light system, size? 364W full spectrum LED

Temps; Between 24-27C

Humidity; 40-55

Ventilation system; 4” exhaust, open windows of tent for intake, 2x6” fans, one inside, one outside the tent

AC, Humidifier, De-humidifier? Had a humidifier in there but hard water residue was plugging up my charcoal filter cover, just using a bin of water now.

I will drop the pH to 6.2 on the next watering. When should I know if it’s helped?

Ok so I have just given them some pH 5.7 water to bring the pH down. Anyone know how long until I’ll see any changes? I assume the old leaves won’t change back, but I’ll watch the new growth.


elcome to our world of growing here at ILGM and to our ever growing and awesome community.


Here are a couple of pics of what tour plant has…

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          ?Nutrient Burn is one of the MOST common mistakes a new grower makes,

The reason for this is, because a newer grower will use a chemical nutrient
most of the time and listen to the directions on the box. This is a NO NO!
Depending on the age of the plant, size, strain and soil mixture you are using
also has a factor. There is no set guideline when using nutrients, but I can
give you a good example to start out with so you will not burn your plants.
It’s always good to start out light, rather than feed heavy. Remember you can
always add more later, but can not take out when you added to much. Chemical
and Organic nutrients differ. Chemical nutrients are more readily available
and can burn way easier than organics can. Organics are easier for a newer
grower to use, most of the time, and lessen your chances of burning your plants.
I recommend not using more than ½ teaspoon of chemical nutrients per gallon
of water. Unless the plants are very big 5 feet+, then it’s safe to use 1
teaspoon per gallon of water. When your plants first emerge you want to wait
at least 2 weeks before feeding your plants, unless your plants are in a soiless
mixture, like pro mix. The cotyledons (its first set of round looking leaves) are
what give the plant its food until they get the first 2 or 3 sets of leaves. If
your plants are in a soiless mixture and are over the first week of age; you can
feed a weak amount of nutrients, like ¼ teaspoon per gallon of water. Soiless
mixtures are different from soil plants and soiless plants need to be fed more
when using this mixture.

I also recommend not feeding more than 1 time a week if using ½ teaspoon per
gallon of water for chemical nutrients. You can feed every other day,( this
goes for chemical and organics) at very weak amounts, but doing this may contribute
to over watering, and for that I do not recommend feeding more than once a week.
Some people feed 2 times a week using like ¼ teaspoon per gallon of water… Use 1/4
strength for first feeding and then go up to 1/2 strength from the 2nd feeding when
using chemical nutrients. It’s very easy to overdo it. When using organics, depending
on which one you’re using, I recommend using 1 teaspoon per gallon of water. When the
plant gets bigger you can work your way up to using more nutrients when the plants
get bigger.

As for soil mixtures, there are a lot of different kinds of soil’s out there. Using a
rich soil mixture is not recommended for seedlings. Seedlings that are under 2
weeks of age you do not want to start them in rich soil, using a seed starter
mixture is one of the safer ways. Seed starter mixtures are weak in nutrients,
so it will not burn the seedlings but will provide them enough to get past seedling
stage, but the downside is you have to transplant into a better soil mixture after 2
weeks of age. If you decide to start with this mixture, do not put your seedlings
into a big pot. Start them out with using a cup or a small pot.

Nutrient Burn causes leaf tips to appear yellow or burnt. They can also be brown
and twisted and crispy looking. Depending on the severity it can show many different
symptoms and shows on lower part of the plant when its young, at older stages it
can move anywhere on the plant. The burn will creep into the center of the leaf
causing it to curl and dry up. It depends on the specific nutrient that is in excess.
For example, too much nitrogen causes leaves to curl downwards and too much potassium
creates brown spots near the edge of the leaf. Either way, nutrient burn may potentially
kill your plant or lead to it having a strong chemical taste.

To fix the problem when you have Nutrient burn, you want to flush out the plants
with lots of water.


Soil should be flushed with lots of water, Use 3 gallons of water per one gallon of soil.
Flush very thoroughly, after plant recovers usually after a week, you can resume using
nutrients after a week or a week 1/2. When you flush your soil, you flush everything out,
a lot of nutrients go with it, including the soil nutrients.

Hydro `````````````````
Change out the reservoir, flush out any lines and clean out the entire system and
replace with plain water for the first hour, then start out with lower parts per
million (PPM)
Its good to clean out your system every 2 weeks and replace with fresh water and
nutrients. Some people change everything every week!

Ahh, nute burn! Stop this by not adding to much chemical/organic nutrients to your
water,foliar feeding. DONT feed more than 1 time a week unless using weak amount,
use 1/4 strength for first feeding and then go up to 1/2 strength from then on when
using chemical nutrients. Its very easy to overdo it. Causes leaf tips to appear
yellow or burnt. NEVER give nutrients to plants that are under 2 weeks of age, at
this age the soil nutrients are enough to suppliment them untill 2 weeks of age or
more depending on how good your soil is. Using ferts before 2 weeks will almost
likley kill your plants.

I hope this is the right thread for what I’m about to ask. Including a support ticket. Is this a Magnesium issue? If so what steps need to be taken to correct? Thanks in advance.

Strain? ILGM Amnesia Haze Auto

Photo or Auto? Auto

Soil in pots? Kind/FFOF in 5gal fabric

System type? Water only

PH of runoff or solution in reservoir? NA

What is strength of nutrient mix? NA

Indoor/Outdoor? Indoor

Light system, size? Budget LED 250 R-Spec

Temps; 75-81F Day 65-70F Night


Ventilation system; Yes Vivosun 6" inline w/Vivosun charcoal filter

AC, Humidifier, De-humidifier? House A/C

Or is it possibly an Iron deficiency?

Coco Ph needs to be lower than soil as mentioned earlier.
The nutrient line you are using gaia green dry amendments is all organic stuff and looks like a well rounded line. So what exact product/s are you using from them? Did you charge the coco (mix in dry nutrients) in the beginning or just straight coco and top dressing nutrients before watering?
I didn’t see on their web site any details about using their nutrients in coco and process or recommended PH with coco and their nutrients.

As far as how quick any corrections you make assuming they are what’s needed will take time to notice. What you want to be looking for is leaves that looked normal before correction starting to turn off color or spotting etc. Issues don’t usually happen quickly and fixes don’t either. Are you brewing any teas to help keep up the critter population?

Looks like it could be low in Magnesium. You could add 1 tsp (5-7 grams) so up to 1/2 Tbsp per gallon into your next watering it won’t hurt but can help.
Iron deficiency from what I’ve come across is not very common.
What other nutrients are you planning on adding during the grow? Kind should have enough nutrients for harvest but you wanna have a plan if/when they call for things. Better lights make them more hungry and many times they go through Magnesium quicker than with less efficient lights.

If you’ve used 1 5lb bag of Kind per 5 gallon pot that’s more than enough for them being Autos. Heck I would probably follow up with another round of Autos into same pots right after harvesting…no till style as there will be plenty of left overs for an Auto or even a Photo that you flip early.

I’ve brewed teas and used with Kind to help keep the critters busy.
Spoke with Phil at Kind about that awhile ago and wasn’t opposed that that. The directions provided are to keep new growers from using any nutrients like chemical one’s especially and even organic so as to have an easy grow. The reason I do add nutrients is later in flower using slow release organic to start the re amending process for the next plant into that same soil. Still figuring things out but have about 12 plants going from that and some are doing great others not so well.

1 Like

I am using Gaia green 70/30 4-4-4 & 2-8-4. I amended the medium before planting with 4 tbsp per gallon of medium. I top dressed with 2 tbsp per gallon at day 30 with a 50/50 mix. I plan on top dressing at day 60 with a 30/70 mix and a some bat guano for the mid-end of flower. I have been watering at 6.5-6.8 since day 1. These changes started a few days after I top dressed the first time.
I haven’t grown organically before and I am following advice from a YouTube guy called mrcanucks. I basically followed everything he has suggested. I feel like my top dress increased my pH so I’ve added a small amount of pH 5.7 water (about 1 cup per plant) to try and even out the existing moisture that is in there. The buds are still getting fatter and there is still some decent growth, though it seems that they aren’t growing upward a lot, but adding mass. I know it will take a couple days to see any difference. I hope it will do some good and if it doesn’t, I may see the problem more clearly. Oh and I’m using a 364W full spectrum LED from quickgrow.

Thanks for reply. After doing a little interwebbing I think I know my issue. It seems it may be a case of over watering and combo of possibly too much light, although I check the weight of the pot and feel the bottom to see if it’s dry or wet. I have given it a couple of substantial waterings the past two times three days apart. I’m using 3lbs of Kind soil with FFOF on top in 5gal pot I have no plans of adding any nutrients that’s why I went with the Kind soil. I do have fox farms nutrients just in case. Water going in last watering was at 7.0ph. I took a soil sample and did a slurry and got a reading of 6.0 but that was a couple of days ago.

I’ve seen some of his videos and he know how to grow from what I’ve seen.
Does he Ph water? What does he recommend for a Ph? Does he recommend using RO or just any old water? Someone else on this forum had mentioned running their grow based on that video you saw not not sure who it was. Maybe search tool above look for Gaia green and maybe you’ll find the posters journal.

I figure you’ve watch that series several times but maybe a refresher look to pick up more good knowledge.

I might consider giving them enough water for a small amount in saucer. Give that run off time to wick back up and if not all gone in 30-45 minutes then dump out left over. If it gets sucked up in 5 minutes add some more to saucer and see…rinse repeat This way you ensuring the entire medium is moist not just the top and middle.

Autos do their own thing as far as when they stop veg and go bloom if when seedlings they had any issues and were slow going that can affect the size they get before going to flower. Just from seed to seed they can all be different. If they’ve already went through their stretch (growth spurt when transitioning from veg to flower) and you would know the end of transition by the buttons that form on tops are defined.
They will fatten up as that’s where all their energy is focused on to make sticky tops to catch pollen to make seeds to reproduce next season. So that’s great.

Original pics I see calcium on left leaf…tip burn is not that big a deal unless it keeps going like a lit joint.
Looks like potassium on the bottom pic.

One thing to consider is the amount of nutrients you top dress as I would think you would want to add or subtract amount used taking into consideration the plants mass…bigger plants eat more and drink more.
Just a thought…if it’s not broken…ya know

1 Like

@registereduser Honestly, the light green pic will either be Nitrogen def or simply light def. try simply moving the light green leave plant closer to your light source. Remember it’s an Auto and they begin flowers, usually at 3 weeks old. They grow really fast and new growth will be light green also. That is normal, but that bigger leave I found out in my grows was either far from the light or Nitro def. Good luck on your grow and welcome to the best grow forum on the internet!


I appreciate both of your comments. I have maybe over watched a lot of the videos and searched for a lot of others that use the same method. The only thing I seem to be off on was my water pH at 6.5-6.8 though mrcanucks does recommend that range, he changes his tune in newer videos to 6.0-6.2. The one thing I know won’t happen is the issues won’t go away, they just will either stop All together or continue to get worse. Though I hope to keep things in good condition and will do everything I can do keep things good, I also appreciate the learning that comes with it. I will also take the size of the plant in to consideration. I hadn’t really considered that. I figured it was the life of the organic nutes, but I realize now that they have been in the bag for a longer time, so that assumption is fairly dumb on my part. Lol

1 Like

Something I forgot to mention, with autos in a 3-5 gallon pot or bag, I usually don’t begin nutrients until about 3 weeks into flowering and def only once a week if I get 2 waterings a week. I use Fox Farms Ocean and they are usually hot to begin with. I start with 1/2 nutes for 2 feedings then go to full nutes after that so she gets used to the amount and uptake. If the first round at 1/2 nutes burns her tips then I do a light flushing and reduce to 1/4 nutes.

She is growing in a coco medium using dry organic nutrients so makes things somewhat different regarding when and how much to feed. The critters in the medium break down the nutrients and feed the plants.

1 Like

Thanks @TokerGuy I’ll try that and see what happens.

1 Like

So, since I was seeing multiple different potential issues with the yellowing and spotty leaves on two of my girls, I felt like it could have been any of the NPK deficiencies or a pH issue. This bothered me because I had JUST amended the top soil a few days earlier and I had been following recommendations to keep the pH at 6.5-6.8. This got me thinking. So, what I did was I pH’d my water to 6.0 based on some new info I read (not sure how I missed that before) and I re-mixed the top soil a little more. You see, the top of the medium was a little crunchy and flat, and I think I may not have mixed it up in to the top soil enough when I amended, therefore the girls weren’t getting any food. I did not add any nutes or anything, just mixed it up a bit more, broke up some chunky pieces and watered at 6.0. They are not showing any signs of issues now besides what had already existed. So, I think I made the right call. :grin:


They look gorgeous to me!

1 Like

Day 41 from seed. These girls are going to pack on some weight despite their short structure.