Burnt leaves! Nutrient Burn?!


I am a first time grower and went with the autoflower sour diesel from ILGM. I am at about week 7 of growing and my plant have begun to flower. I am growing the plant partially indoors and on my balcony. They get natural sunlight throughout the day. The soil is fox farm ocean forest. I am also using the fox farm soil trio nutrients. I only use 1/3 the amount of nutrients which is directed on the schedule. My leaves are now starting to have burn spots and the edges are turning brown. Is this just a nutrient burn or is there some type of deficiency? Please help!


Looks like a touch of nitrogen toxicity (burned tips, dark leaves, and clawing.) Leave out nitrogen for a feeding or 2 to give the plant a chance to recover. Nothing to worry too much about.


Do you test TDs and Ph in run off ?? If not search it here and read up on it as you should be.

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Thanks! both tiger bloom and grow big have nitrogen in the mix. I will exclude those for a few feeds and see if that makes a difference.

I just put in Poland Springs water at 6.71 ph and the ph runoff was at 5.83.

TDs is ???

Hi Cms7889 and welcome! I agree with MidwestGuy and would like to add that you may also have a pest problem. Some of the markings on the leaves resemble bugs. Look closely with your magnifying device, especially the underside of leaf. I hope that I am just seeing things and I wish you good luck!!!

Correct! I had a spider mite problem which was transferred to my plant from a palm plant in my apartment. I treated this with neem oil/dish soap/water based on other forums. I have been checking under the leaves since then and don’t see any more signs of spider mites. The white spots on the leaves are left over from that.

I do not have a TDs meter. Do you recommend buying this?

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Yes. It’s the only way that you can properly manage nute levels.

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Welcome to the community

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What he said! midwestguy.

Thanks all!! This is very helpful. I just ordered a TDs meter. Do you normally pull soil from pot and mix with water and then filter it to test the ph and TDs? Or do you just test the runoff after watering? What ppm do you generally want your TDs to be at during flowering and how do you adjust it?

You can do this. It is called a slurry test.

Yes. Catch runoff from the watering and test it. This is called a runoff test and is equally accurate.

In flowering? A PPM of 1000 to 1200 is where you want to be.


Perfect! Also ordered that along with the meter. Will follow up with any changes and my levels once the meter comes. I always test the ph before watering the plant. Do you also test the TDs of the water/nutrients before giving it to the plant?

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So I got the TDs meter and completed a slurry test.

PH 6.95 and 35 ppm

PH 6.09 and 903 ppm

I have not fed the plant any nutrients since we last talked and have been giving it distilled water only. Any suggestions or should I still with you original suggestion and remove nitrogen from the next few feeds?

Your slurry test was done with equal parts distilled water and soil that sat for 24h?

Midwest has you covered. Just wanted to add that and another point on lockout. Dark green is first, then waxy means you’re even closer. Some plants are just darker than others, it’s the waxy that really tells you. Also for runoff tests you want to discard the first ~5%. Don’t want ppm readings thrown off by built up salts.

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I make it easy. I Ph and TDS my tap, then with neuts mix, then the runoff. I record them in my notes and track them as for any changes. If you get salt build up you will be able to see it in your readings. The way I understand it is …ph tells you the ability to take in neuts and the TDS tells you how much neuts are left in the soil. Now you can feed according to the plants needs as opposed to just a schedule not necessarily appropriate to your plants.

Yes the slurry test was done with equal parts of 6oz of Poland springs and 6oz of soil from close to the root and sat for 24hr

I guess the only part I am having difficulty understanding is which nutes I should actually give it to make it correct and the range I should be in for ph and ppm. So if my ph is decreasing in the run off to 6.09, would I want to add ph up so that it is higher when it goes in and the runoff is around 6.8? Or is 6.09 in the runoff fine. And if the ppm after I add the nuts to the water is around 1000-1200 what should I expect the runoff to be if it is taking in the nutes well? I am researching online but not finding very good information on nutes and TDs