What causes this problem in cannabis plants??? (PICS)

[jimihendrix1]

I agree theres much better fertilizer, and Id look into changing ferts.

Yes I would keep giving the Cal/Mag. I would also check PH if you havent. If your fert doesnt have adequate, or any Cal/Mag in it, and Calcium, and Magnesium are ESSENTIAL ELEMENTS, why would you not want to supply it.?
Also do not let your plants get bone dry. When you do this, you concentrate the fertilizer, and then when you water/feed again, all your doing is concentrating the fertilizer, and will burn them up. Never let them get to the point they droop. ANY.

Magnesium is one of seven essential macrominerals. These macrominerals are minerals that people need to consume in relatively large amounts — at least 100 milligrams (mg) per day.
Magnesium is extremely important to both plants, and humans. for one, Magnesium, is an Electrolyte, as is Calcium. Sodium, Potassium.
Magnesium helps in the formation of bones and teeth, regulation of blood pressure and blood sugar levels, helps in muscle recovery, and nerve regulation, and also helps in the formation of various proteins and DNA. It also helps in mood regulation and plays a major role in various metabolic activities in the body.
Magnesium plays a role in over 300 enzyme reactions in the human body. Its functions include helping with muscle and nerve function, regulating blood pressure, and supporting the immune system.
An adult body contains around 25 grams of magnesium 50–60% of which the skeletal system stores. The rest is present in muscle, soft tissues, and bodily fluids.
What is hypomagnesemia?
Hypomagnesemia, also known as magnesium deficiency, happens when you have a lower-than-normal level of magnesium in your blood. It can be mild or severe.

Magnesium is an electrolyte that’s a key part of many bodily reactions that affect cellular function, nerve conduction and more. Your brain, heart and muscles rely heavily on magnesium to do their job.

Magnesium has a direct effect on the balance of other electrolytes, including sodium, calcium and potassium. Hypomagnesemia often happens alongside hypocalcemia (low blood calcium levels) and hypokalemia (low blood potassium levels).

It should be noted that while most of your body’s magnesium is stored in your bones, it’s only the magnesium dissolved in extracellular fluid (mostly blood plasma) that’s available for use by cells and organs.


What's the Function of Magnesium (Mg) in Plants?

Magnesium is also a critical macronutrient for plant growth and health. It is a key element of the chlorophyll molecule – essential for photosynthesis.

Magnesium gives leaves their green hue and activates most plant enzymes needed for growth while contributing to protein synthesis.

This is merely the surface of how magnesium benefits your plants. However, it is easy for something to go amiss in your garden if this macronutrient is lacking.

IMHO what you have is more of a Calcium Deficiency, along with a Mg deficiency.

 

[Kush Inc.]

You use synthetic nutes and you don't PH your water, is that correct?

 

[nxsov180db]

Magnesium and Calcium deficiencies will show other signs before it gets to the point that the leaves disintegrate like that. Calcium you'll see rust specks on the older growth as the first sign. Magnesium the leaves will get lighter green while the veins will remain a darker green. That pre harvest pic you showed is a classic P-K over feeding. Both your P and K are high but I believe your P is causing the most damage.

 

[VaSmile]

Damage from cal/mag deficiency will not heal. And those deficiency are present about 4 weeks before symptoms show. You'll be feeding cal mag for at least a week before new damage stops.
I use cutting edge solutions 3part and the micro mix has more cal and equal mag as most calmags on the shelf

You use synthetic nutes and you don't PH your water, is that correct?

Fuck no I don't ph my water I did it once and I hate those pens. My tap is 7.2 and my full bloom mix is 5.6. I adjust my nute is small increments after 3 or more waterings so they only have to adapt to a pH change of about 0.2. Once I get to a nute level I know has a pH of below 6 I had 1 ml of up which raises pH about 0.5. I dont have ph issues

 

[calvin.m16]

You didn't mention what pH your setting your solution to before watering? Jacks sucks for small grows bro, its more meant for large stock tanks and its hard to dial in when your feeding small amounts at a time. I have gone through 50 pounds of Jacks RO formula before I said fuck this shit and switched back to General Hydroponics MaxiBloom. Constant issues, not a real 1 part when it comes to jacks you need epsom salts and other additives to make it actually work.

 

[calvin.m16]

Damage from cal/mag deficiency will not heal. And those deficiency are present about 4 weeks before symptoms show. You'll be feeding cal mag for at least a week before new damage stops.
I use cutting edge solutions 3part and the micro mix has more cal and equal mag as most calmags on the shelf

Fuck no I don't ph my water I did it once and I hate those pens. My tap is 7.2 and my full bloom mix is 5.6. I adjust my nute is small increments after 3 or more waterings so they only have to adapt to a pH change of about 0.2. Once I get to a nute level I know has a pH of below 6 I had 1 ml of up which raises pH about 0.5. I dont have ph issues

PH is more important than what you feed the plants, starting water pH has nothing to do with your pH after you mix nutrients. You can't defy nature, anything below 5.8 pH is too acidic for a cannabis plant.

 

[calvin.m16]

I used to run HPS and if you have a deficiency or a pH issue (causes deficiency) your leaves will cook so fast your head will spin. I would change to a more dialed in fertilizer program and not add more than they suggest. If your running Jacks' without shittons of epsom salts then there is your issue. That shit doesn't contain any sulfur or magnesium. Honestly jacks has the worst fertilizer profile of any brand I have ever encountered or ran.

Their RO "one part" is a complete fallacy you still need to buy epsom salts or your plants will eat shit and die.

 

[VaSmile]

PH is more important than what you feed the plants, starting water pH has nothing to do with your pH after you mix nutrients. You can't defy nature, anything below 5.8 pH is too acidic for a cannabis plant.

Safe ph range for soil is considered to be 5.6-8.4 a large adjustment say 1.1ph would cause shock but 0.2 is not a big swing and 1.1 though out the whole life span is not extream.
If time was a major issue I would hold a constant pH and jack my nutes up at 2-3 times the speed that I do. I give each girl her own tent so I don't have to worry about running on a schedule and idc if veg takes 8weeks instead of 6 low and slow is safe.
Thanks for the info on the Jack's. Thinking I'm gonna switch off the CE and look for something that's 2part and cheaper but I guess I'll look at GH and FF

 

[ebgms]

1. Cal-Mag is a supplement, not fertilizer, just feed it with every watering unless the fertilizer has cal-mag in it.

Yes that's what I'm doing now, 5ml CAL-MAG per gallon every watering. Is it a good idea to apply CAL-MAG during veg as well or only in flower (my plants do great in veg w/o it)?

2. Two days of cal-mag is not enough time to work. Magnesium deficiencies exist 4-6 weeks before any physical symptoms first appear.

Wow. Is there any way of detecting it other than physical symptoms?

3. Why are you still feeding Jacks fertilizer? It seems like the constant input in this death march is the fertilizer. I would try switching to something complete and easy to use. I like GH Flora Nova, 1 bottle for veg, 1 bottle for flower. Cal-mag and everything else included. Mixed to the correct strength and the ph will be balanced as well.

I am planning to switch to either GH Flora or FoxFire Bloom Big/Tiger Bud fertilizer for flowering on my next grow. I've never run any one of those nutes though.

The combo Jacks Classic 20-20-20 for veg then Jacks 20-20-20 plus Flower Fuel 2-34-32 worked well for me for many years, but perhaps it no longer will.

It does sound nice having nutes that are specifically formulated and pH-ed to cannabis instead of just plants overall, like with the Jacks.

4. Get a good ph meter and use it every time you water. Ph to between 6.4 and 6.8 in soil.

I just got a pH test kit and some pH down in the mail today. I'm going to experiment with it tomorrow and over the weekend. I might post a thread in the newbie section about it, since although I've grown for many years I'm a total newbie to "pH-ing the plants" or w/e.

5. Use good, fresh potting soil, especially to repot before you flip to flower. I repot from 1 to 3 gallon, and flip in a few days.

This is almost exactly what I do also. Veg in 1gal nursery pots, pot up to 3gal, veg until the first need to water them in the 3gal then flip.

6. Do not expect to rescue the current death march, the leaves will not recover and it's too late to grow new leaves. Just do the best you can and plan a different regimen for the next grow.

Good to know. Sad, but good to know.

7. Please refer to this chart for more information:

Already stolen and in my toolbox. Much appreciated.

 

[ebgms]

If you're feeding 3 grams of 20-20-20 and 1 gram of 2-34-32 you're feeding about 110ppm of Phosphorus. Anything over 100ppm of phosphorus is in the toxic range. you might be feeding even more than that, im just guessing that 3/4 of a teaspoon is 3 grams and 1/4 is 1 gram.

How do you calculate ppm of each of the three elements from total grams per gal and an NPK ratio?

 

[ebgms]

I agree theres much better fertilizer, and Id look into changing ferts.

I'm planning to either go with the GH Flora system or the FoxFire Big Bloom/Tiger Bloom system on my next grow during the flowering phase as both seem highly recommended on here.

Yes I would keep giving the Cal/Mag. I would also check PH if you havent.

Will keep feeding Cal/Mag. Just got pH test kit in mail today, going to play with it tomorrow and over the weekend.

If your fert doesnt have adequate, or any Cal/Mag in it, and Calcium, and Magnesium are ESSENTIAL ELEMENTS, why would you not want to supply it.?

I just want to make sure I'm giving the right amount and not over-doing it is all. The directions say 5ml per gal so that's what I'm doing.

Also do not let your plants get bone dry. When you do this, you concentrate the fertilizer, and then when you water/feed again, all your doing is concentrating the fertilizer, and will burn them up. Never let them get to the point they droop. ANY.

Yeah I think I was messing up here for YEARS, because I would wait until I saw visible drooping before even thinking of watering them. I killed several plants years ago when I was a "newbie" to this by over watering so I have always been very cautious about it.

I'm using a moisture meter now that ranges from "dry" through "moist" and maxes on "wet". I'm now watering when the meter is on the low end of "moist" but before it hits "dry".

[a whole bunch of useful and interesting info about Magnesium]

Wow that's amazing that Mg is involved in so many life processes. I had no idea how important (essential really) it is to life, both to plants and humans.

 

[ebgms]

You use synthetic nutes and you don't PH your water, is that correct?

Yes, but that's about to change.

Love your avatar btw.

 

[ebgms]

I have gone through 50 pounds of Jacks RO formula before I said fuck this shit and switched back to General Hydroponics MaxiBloom. Constant issues, not a real 1 part when it comes to jacks you need epsom salts and other additives to make it actually work.

Do you mean you had/have constant issues with Jacks or GH MaxiBloom that you had to add Epsom salt?

 

[ebgms]

I used to run HPS and if you have a deficiency or a pH issue (causes deficiency) your leaves will cook so fast your head will spin.

Yup, they've definitely been cooking, and my head's definitely been spinning.

I think over the ~4 years I've had this problem my HPS has done more "cooking" than Emeril Lagassi.

Thank you for the info and the replies.

 

[calvin.m16]

Do you mean you had/have constant issues with Jacks or GH MaxiBloom that you had to add Epsom salt?

I have had zero issues with MaxiBloom I had nothing but issues with Jack's. Lots of head scratch wtf days where leaves looked off and I couldn't figure it out because my notes didn't change much on what I was doing. I switched to maxibloom and have no problems other than you gotta watch out for acidic rootzone which just simply means keep your pH in the 6.0 range when you feed. I also do give the plants a couple flushes through flower with plain water to help prevent any toxicities or buildups just precautionarily.

 

[Nizza]

start with the basics, pH (if not in buffered soil) , adjusting PPM to suite the appetite of the plants, and the proper ratio of nutrients including micro and macro nutes I.E a complete diet

runoff method is great for me in coco but in other mediums it may or may not be needed. I run multiple strains per grow so the runoff does allow leeching off of nutrients that strain may not be eating. +1 to coco coir

after buying the tools to pH and ppm check my water, automating my watering was the biggest game changer (besides environmental control during late flower/ drying)

one fun thing to learn is that plants will uptake less nutrients or more nutrients in an uneven cycle until being able to control your environment

 

[calvin.m16]

start with the basics, pH (if not in buffered soil) , adjusting PPM to suite the appetite of the plants, and the proper ratio of nutrients including micro and macro nutes I.E a complete diet

runoff method is great for me in coco but in other mediums it may or may not be needed. I run multiple strains per grow so the runoff does allow leeching off of nutrients that strain may not be eating. +1 to coco coir

after buying the tools to pH and ppm check my water, automating my watering was the biggest game changer (besides environmental control during late flower/ drying)

one fun thing to learn is that plants will uptake less nutrients or more nutrients in an uneven cycle until being able to control your environment

I agree with this big time also not all coco is the same, some coco coir is pithy, some is fibery, some holds a lot of water (pithy) and some drains off super fast and dries out quick (fibery) and this is all stuff you'll have to adapt watering styles to based on what you can source either online or locally.

Low speed drip feed like 0.3 gph drippers are so beautiful because they almost defy this issue by feeding so slowly that it saturates from the stake out nice and slowly and gradually. I definitely will be switching to all netafim drip feed by next month. I just setup a whole barn with it and the plants are LOVING it in pure coco.

 

[Drop That Sound]

With Jack hydro 5-12-16 (not sure about the RO formula..), you pretty much have to mix up stock solutions, no matter how you grow IMO. If your measuring out little scoops each time, like enough to make 4-5 gallons, its not going to be fully balanced. Lets say you need 12 grams, but you accidently scoop out 13.5.. When you go to tap a little bit out of the scoop and back into the bag (I know I used to!), it sifts the bigger grainier chunks up and out first, and throws off the ratios. If you shake the big bag around, all the big white chunks come up to the surface, and then you scoop more of them up if your not careful. I try not to move the bag much (25#), so it doesn't do that. Never heard anyone ask about it, or any warnings.

You shouldn't really be mixing salts all the time anyway, or breathing it in if possible anyway..


On the other hand, when you mix a 1 gallon stock solution up, you pull out big scoops to add in, so overall its more balanced out. Plus, it has more time to fully dissolve, and less likely to precipitate when mixing both parts..

I think it might be one of the main reasons small time growers have problems with Jacks hydro blend.. Mixing up really small batches, with small scoops of part A..

 

[Driver733]

Yes that's what I'm doing now, 5ml CAL-MAG per gallon every watering. Is it a good idea to apply CAL-MAG during veg as well or only in flower (my plants do great in veg w/o it)?

I used to feed cal-mag as a supplement when I was using Fox Farms nutrients, now I use GH Flora Nova which has cal-mag in it already, for veg and flower. You won't burn the plant (* unless you use way too much *) like you can giving too much fertilizer, you want the cal-mag there when the plant needs it.

Wow. Is there any way of detecting it other than physical symptoms?

No, and even if you could you would be 4 weeks too late. Best to feed it, like taking a daily vitamin.

I am planning to switch to either GH Flora or FoxFire Bloom Big/Tiger Bud fertilizer for flowering on my next grow. I've never run any one of those nutes though.

Stay away from Fox Farms, nothing but problems for me. I switched to GH Flora Nova and love it.

I just got a pH test kit and some pH down in the mail today. I'm going to experiment with it tomorrow and over the weekend. I might post a thread in the newbie section about it, since although I've grown for many years I'm a total newbie to "pH-ing the plants" or w/e.

When you get tired of messing with the test kits, spend the money for a good pen. I use Hanna, after using several cheap pens, not worth it. Go for the good pen first and don't waste money on the cheap ones. Yes, the Hanna cost $225 now on Amazon, and worth every penny IMO.

Already stolen and in my toolbox. Much appreciated.

You're welcome. Stick with it, you'll figure it out. Good luck!

 

[ebgms]

But back in the late 70s-90s we grew plenty of killer weed with Miracle Grow 20-20-20, and Peters 20-20-20, and used 5-50-17 bloom booster.

I was just re-reading the thread to see if I missed anything and this caught my eye.

Dam I was born in the 80s, grew up in the 90s and you were growing weed in the 70s??? I didn't even know what weed was until the early 00s!

That's absolutely amazing that you figured out how to do it back then with no internet, no video, no books, no rollitup forums etc to ask questions if (when) things go wrong...wow.

Mad props and respect for pulling that off Sensei!

And back then we used a lot of topsoil, and added both Calcitic, and Dolomitc Lime to the soil, so they got both Calcium, and Magnesium in that way.

I think on my next grow I'm going to add some dolomite lime to my soil before I transplant them into the pots they will be flowered in. From what I understand this has a dual benefit: Buffers the pH and provides a source of calcium. I'll look into the calcitic lime too if I can find it. Thanks again for the info.