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Sever leaf burn on a few plants!

blackg0d

Member
Using 65-100 gal soil pots outdoors under greenhouses. Decent sun but far from full sun. Supplemental lighting. Empire builder soil (high quality). GH flora series expert line of nutes. Feeding every other watering. Watering close to every other day. Always checking PH with Hanna Combo pen. Sprayed with flying skull nuke em quite often, but always as directed, in the evening after sun goes down and lights are off. Seeing some extremely burned leaves on several plants in random areas of the garden, with almost no warning signs ahead of time, seemingly came out of nowhere. Some leaves have had that burnt edges look but some of them just straight up fried. Some stems looks almost diseased. Affected plants are not drooping. Rest of garden looks very happy. My only thought is that the soil has an abundance of one nutrient that we are also feeding it, and that nutrient has become over abundant in the soil. Checked the ph of the soil today and it was 6.3/6.4 in pots of affected plants and non affected plants. Our ppm's on our feeds have been consistently around 800 lately, and definitely have not risen above 1500. Our feed during veg was a little bit higher of a number than it is now. Any ideas IC? If not nutrient burn then I'm stumped.
 

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blackg0d

Member
Is that how it works? That would make sense. Less photosynthesis throughout the day, less ppm's are being absorbed by the plant, more are building up in the soil.
 

slownickel

Active member
ICMag Donor
Veteran
Using 65-100 gal soil pots outdoors under greenhouses. Decent sun but far from full sun. Supplemental lighting. . Rest of garden looks very happy. My only thought is that the soil has an abundance of one nutrient that we are also feeding it, and that nutrient has become over abundant in the soil. Checked the ph of the soil today and it was 6.3/6.4 in pots of affected plants and non affected plants. Our ppm's on our feeds have been consistently around 800 lately, and definitely have not risen above 1500. Our feed during veg was a little bit higher of a number than it is now. Any ideas IC? If not nutrient burn then I'm stumped.

If your nutrients get out of proportion to calcium, this is the result. You don't have to have high conductivity to cause problems. More sodium than potassium in your distribution of bases will do this. Excess Mg will do this.

Add some gypsum. Send in a soil sample so you can learn what you did wrong.
 

blackg0d

Member
FYI we are in week 6-7 since we started flowering. Hard to say exactly because they took a while to really start budding and some of them are still barely budding. I'm not sure if you count the week from when you turn off the extra lights, or from when they show signs of flowering. It seems like there were almost 2 weeks of transitioning.

Hey thanks for the informative reply, there's always more to learn. So when you say nutrients out of proportion to calcium, does that mean too much or too little calcium? And more sodium than potassium, does that mean an excess buildup of salts? Is this unrelated to overfertilization?

The dark green is a good point, Arf. I didn't really consider that till now. Everything should be yellowing at this point.

One more thing I wanted to add is that in addition to our soil already being pretty rich before feeding, we have watered with compost tea once or twice. A low dosage at that. I honestly don't know much about it or if that would make any difference.

Currently we are giving everything a few doses of just Ph'd water. Hopefully some flushing will do the job. But please tell me more about Gypsum and why you are suggesting it. Would using a flushing agent like FloraKleen help to get rid of some salts? Supposedly you can use it in between nutrient changes.
 

LostTribe

Well-known member
Premium user
I dont know shite about OD but you might PM foothillsfarmer he's an Einstein on anything OD. Tell him I sent you, but he's super busy cropping out right now.... They do look overferted. What is your soil PH?
 

Bongstar420

Member
For Calcium, I relate the ratio of P, Mg, S, and Micros

The ideal ratio varies between specimens and growth stage. There are other important ratios, but they are not relative to Ca.

Gypsum is a good way to boost Ca and S levels without causing burn. It is mostly insoluble and gets absorbed as the plant works on it. It has a neutral effect on Ph.

I don't see a point to flushing agents besides separating you from your ca$h. If its insoluble, the plant doesn't "see" it unless it does work on it.

High Ca and S will give you NPK deficiencies...You look like to much Ca and S but that is hard to say without seeing what you put into it in the first place.

You should do your best to avoid Na.

FYI we are in week 6-7 since we started flowering. Hard to say exactly because they took a while to really start budding and some of them are still barely budding. I'm not sure if you count the week from when you turn off the extra lights, or from when they show signs of flowering. It seems like there were almost 2 weeks of transitioning.

Hey thanks for the informative reply, there's always more to learn. So when you say nutrients out of proportion to calcium, does that mean too much or too little calcium? And more sodium than potassium, does that mean an excess buildup of salts? Is this unrelated to overfertilization?

The dark green is a good point, Arf. I didn't really consider that till now. Everything should be yellowing at this point.

One more thing I wanted to add is that in addition to our soil already being pretty rich before feeding, we have watered with compost tea once or twice. A low dosage at that. I honestly don't know much about it or if that would make any difference.

Currently we are giving everything a few doses of just Ph'd water. Hopefully some flushing will do the job. But please tell me more about Gypsum and why you are suggesting it. Would using a flushing agent like FloraKleen help to get rid of some salts? Supposedly you can use it in between nutrient changes.
 

slownickel

Active member
ICMag Donor
Veteran
Send in a soil sample and learn now. It will cost you less than $50 and you will know immediately why you need to add calcium

Go read at the Slownickel Lounge where I have written it out, it is a bit lengthy. If you are interested, you can download a great book regarding why Calcium at the soilandhealth org page, free library. Tiedjens, More Food from Soil Science.

If you download some of the files in this forum, THC levels were THE HIGHEST by more than three times in the highest calcium soils with low Mg. And from the different soil analysis data base we are forming with growers on here, it is real easy to see why the best are the best. Maui for example, 81% Calcium naturally occuring and he needed more due to sodium problems!
 
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