Plant after plant, the same issue that I cannot figure out. Please help!

[BallsackSal]

@Proph Is this issue just as prevalent in photoperiods?

 

[TheCannaZombie]

"Cal mag" isn't even a word...

I only add calmag (not a word but the product description) if needed. Hardly ever. I have not added any to these plants, but have tried on the last one that did this. I am sure it is locked out of something. I never had issues with the one part doing this. The two part seems to be my issue. These are in flowering, so they are getting very little part B which is what has the Ca in it. It only seems to happen in flower, when I am lowering the N and Ca. This would leave me to believe that it shouldn't be too much Ca.

Can you recommend a better nutrient that is easy? I do not want to use 12 different bottles to make sure I am getting all my nutrients.

 

[TheCannaZombie]

@Proph
Reading more into the 2 part, when I adjust for flowering, my Ca is down to 5.3% from 9.5% but my Mg is up to 4.5% from 3.1%.

I have been trying to read on the proper nutrient values for cannabis, but there isn't any good evidence for it yet. One day it will be like Corn where we know the exact interactions for each variety.

Here is what I am working with. Early veg I am feeding at NPK 11.65/4.77/9.53. Late veg, 10.25/6.5/13. Flower, 7.94/9.36/18.72. With each change, Ca goes down and Mg and S go up substantially. All of these were adjusted to keep the same NPK ratio recommended by Greenleaf to me but to lower the PPM to 250-550 depending on which stage I am in.

I do understand nutes a little bit and understand CEC and cations. I understand selectivity and retention. Well, as well as a third-year soil and plant science student can anyways. So I have the basics down, but I am sure I am missing something. I know that cation exchange sites will attract Ca>Mg>K and release anything with lower selection. So if all my cation sites are filled with Ca and I am not adding any extra outside of what is already in my nutes, is it probably getting too much Mg and locking out K? I am not sure for cannabis, but a lot of crops call for 5/1 ratio of Ca to Mg. If the Mg gets above this ratio, it can cause lockout. This is what I am currently thinking. If this is the case, with my part A being so high in Mg, what can I do? Do I go back to feeding my late veg cycle to keep the Ca up and the Mg lower? I am just at a loss and seriously frustrated. I have been growing for about 2 years now and this is the first time I have had an issue that I could not get under control.

If I do need to flush in coco, what is the best way? I read half-strength nutes at double the volume for a few feedings and then back to full strength. Does that sound right?

EDIT: Grammar

 

[Proph]

@Proph
Reading more into the 2 part, when I adjust for flowering, my Ca is down to 5.3% from 9.5% but my Mg is up to 4.5% from 3.1%.

I have been trying to read on the proper nutrient values for cannabis, but there isn't any good evidence for it yet. One day it will be like Corn where we know the exact interactions for each variety.

Here is what I am working with. Early veg I am feeding at NPK 11.65/4.77/9.53. Late veg, 10.25/6.5/13. Flower, 7.94/9.36/18.72. With each change, Ca goes down and Mg and S go up substantially. All of these were adjusted to keep the same NPK ratio recommended by Greenleaf to me but to lower the PPM to 250-550 depending on which stage I am in.

I do understand nutes a little bit and understand CEC and cations. I understand selectivity and retention. Well, as well as a third-year soil and plant science student can anyways. So I have the basics down, but I am sure I am missing something. I know that cation exchange sites will attract Ca>Mg>K and release anything with lower selection. So if all my cation sites are filled with Ca and I am not adding any extra outside of what is already in my nutes, is it probably getting too much Mg and locking out K? I am not sure for cannabis, but a lot of crops call for 5/1 ratio of Ca to Mg. If the Mg gets above this ratio, it can cause lockout. This is what I am currently thinking. If this is the case, with my part A being so high in Mg, what can I do? Do I go back to feeding my late veg cycle to keep the Ca up and the Mg lower? I am just at a loss and seriously frustrated. I have been growing for about 2 years now and this is the first time I have had an issue that I could not get under control.

If I do need to flush in coco, what is the best way? I read half-strength nutes at double the volume for a few feedings and then back to full strength. Does that sound right?

EDIT: Grammar

We have to be clear on the situation.. If you read your first post, it says you added calmag and that the spots progressed.. Your recent post says you only use it when needed, and that you didn't use it at all on these plants.. Am I missing something?
Just trying to make sure I'm reading right.. Ideal cannabis npk ratios have been known for a long time. Other countries have been growing and studying cannabis for way longer than we've been alive. The cec question is a loaded one.. That's why I said it would be almost impossible to know what to do without a lab test.. Yes, what you described is very possible.. But so are several other scenarios just like It.. It could be an excess of K, locking out Ca, Mg and N.. It could be an excess of N, locking out K and Ca.. With those mega crop npk ratios, everything is possible, lol. They're just way too high in everything. 9% K in veg?? 8% N in flower? *Breathing deep trying to keep to my mega crop promise, lol*.... The most common npk ratio for veg is 2-1-3, and 1-2-3 for flower.. The mega crop ratios are more than twice that.. As far as what to do now.. Your options are super limited.. You can flush, but that will do more bad than good.. You can play with the feeds.. But that's really difficult.. Manogreen has figured out an MC feed reduction process that works for him.. But he's in hydro.. It's such a tough call.. I'm not a fan of flushing unless it's a full flush to zero ppms.. I've never done that with an auto though and wouldn't recommend it. Too much shock with no time to recover.. I would check the ppms of some run off.. Then use 0 ppm water only until that run off number is cut in half.. Regardless of what you do, ones a canna plant is in flower, there is no option for recovery or correction. Leaves don't improve.. You can only hope to stop or slow the spread of the issue.. If your expertise is in soil, perhaps you should grow in that instead. Coco is basically hydro.. Your feeds have to be precise. Any mistakes show up almost immediately.. But if this is your 4th grow like this, it's time to change something.. The medium, the nutrient line, something..

 

[TheCannaZombie]

Not expertise, just knowledge. Not a lot of experience in soil other than vegetables.

My last 4 plants have had this problem. I run a perpetual tent, so I only have two running through this issue now. I have tried other options before to no avail. I have not done anything different with these plants other than normal feed. Some myco and some recharge a few times. Decided to reach out and see what I can figure out before doing anything else.

I hesitate to go to soil. I lose yield and I have tons of bug issues. I work in a field sometimes and get to bring that field home to my plants. When I run in soil, it usually doesn't take long before I have to combat insects. I am open to changing nutrients, but I need something simple. Full-time student, dad, granddad, and having a job... Making stock and keeping plants fed is tough enough without having to measure from a bunch of different bottles. Do you have any recommendations on that end?

Aside from that, I need to figure out what to do now. If I flush down to half PPM, that will not change the ratio of the nutrients I am feeding. Could it keep it from progressing long enough to finish? Should I try lowering PPMs to half through the grow?

 

[Proph]

Not expertise, just knowledge. Not a lot of experience in soil other than vegetables.

My last 4 plants have had this problem. I run a perpetual tent, so I only have two running through this issue now. I have tried other options before to no avail. I have not done anything different with these plants other than normal feed. Some myco and some recharge a few times. Decided to reach out and see what I can figure out before doing anything else.

I hesitate to go to soil. I lose yield and I have tons of bug issues. I work in a field sometimes and get to bring that field home to my plants. When I run in soil, it usually doesn't take long before I have to combat insects. I am open to changing nutrients, but I need something simple. Full-time student, dad, granddad, and having a job... Making stock and keeping plants fed is tough enough without having to measure from a bunch of different bottles. Do you have any recommendations on that end?

Aside from that, I need to figure out what to do now. If I flush down to half PPM, that will not change the ratio of the nutrients I am feeding. Could it keep it from progressing long enough to finish? Should I try lowering PPMs to half through the grow?

Ahhh.. I thought you were actually studying in college or something. I always tell people to go with the grow style that's fits them best.. I only suggested changing because if you do nothing/change nothing, you'll be right back in the same situation next grow..

When you say you've tried "other options" before, to no avail.. Im assuming that means you had the same issues.. Then it says you've done nothing different with these plants... What have you tried differently in the previous grows? What week/day are you on? What brand of coco is it? The purpose of flushing until the ppms are cut in half, is to hopefully slow the spread.. Maybe @Mañ'O'Green can help with the mathematic equations to get MC into a usable range. But yes, I would reduce the ppms of the feeds.. And just to confirm, again, check the ppm of some run off. That number is very important to know before you start any kind of flush.

 

[LAC39]

not sure if you can get Jack’s nutrients where you live. If so give the Jack’s 3-2-1 a try. Very simple, effective, and cheap. Good luck.

 

[TheCannaZombie]

Thank you for all the input. I will check the PPMs tonight and report back. One is at D59 and one at D40. I was using canna coco but swapped to chubby buddha coco. Already has perlite and much cheaper. SHOULD already be triple buffered and good to go, but no telling if they took shortcuts.

I am in school. I retired from the military and cannabis helped me so much with pain I decided I wanted to go to school just to learn more about plants. Now I am on track to be a plant biotechnologist by the end of fall next year. I have had two basic soil classes about soil structure and other basic information. I have another soil class this fall, soil fertility. That will help me a lot I think. Also, entomology and weed science. So maybe back to soil after I learn some more about bugs? Eventually, I would like to genetically alter cannabis, but that is a couple of IQ points down the road.

My first plant, the problem was very light and appeared at the end of the grow, so I did not do much with it. The second behind it started showing soon after around D45-50. I checked my PPMs and they were at 640. Higher than I feed, I reduced feed to 400ppm from 500. Ran through about 50% runoff at 400ppm. It did not slow or halt. It seemed to increase. PPMs were closer to normal. I fed calmag. Symptoms still progressed. Finished with some nice crispy leaves at the tips, but not too horrible. However, the buds were much smaller than I was hoping(though still smoke wonderfully). These next two started showing almost the same time, maybe 2 days apart tops. I only noticed two days ago as my wife was watering.

Based on the issues, they look like K and Ca def. Ca up top and K down bottom. That with the really high amounts of Mg compared to Ca makes me think that I locked them out with Mg. Maybe not, but that is my best guess. Is extra N super bad in flower? I know the plant doesn't need it, but what does it affect? I was thinking about going back to my late veg schedule where the Mg was lower than the Ca.

 

[pg2052]

"Cal mag" isn't even a word... It's not a deficiency, or a sickness.. It's a marketing term used to sell a product. Unfortunately this will keep happening until you learn how nutrients work, and how they work/react with other nutrients.

If you are using a name brand bagged coco, there is no reason to add more.. Bagged coco is pre buffered with calcium because if the cec ratios. I've been working the infitmany posts for a couple of years now... I've seen maybe 3-4 plants that were actually deficient.. 9 out of 10 times the issues are caused by a lockout, due to an excess of something.. 8-10 times, its too much calcium.. Calcium is a SECONDARY nutrient.. That means it's not needed in heavy doses or regularly.. So your coco has calcium already in it.. More is added when you use mega crop.. Then more calcium, plus magnesium when you add calmag... Too much calcium in the medium will make magnesium and phosphorus unavailable for the plant to use.. Too much magnesium will make calcium and potassium unavailable for the plant to use.. That's what you are seeing on your plants.. 3 or 4 different issues caused by a lockout. If that's bagged coco, flushing it probably hurt more than it helped due to the calcium buffer.. Read up on coco cec and calcium for more info.. Coco is, in my opinion, an advanced medium.. It is unforgiving, and you have to know you stuff when it comes to feedings. I told myself a few years ago that I would not say another bad word about mega crop because so many people get defensive over it.. but in my honest opinion, is that it's not a good cannabis product. The npk ratios are way off and so are macro nutrients.. I know 3-4 people total that can grow healthy plants with it, and they are all in hydro setups and they had to find there own ratios and feed rates..
Nutrients have to stay in balance.. Once there is an excess of something.. Issues start to show up... And with autos there is zero recovery time.. Once an auto is flowering it's full steam ahead.. You won't be able to correct leaf spots because the plant is no longer focused making or maintaining the leaves. I would say stop adding calmag (forever, like, never use it again, lol).. If for some wild reason you ever need calcium.. Add a source of calcium.. If you need magnesium.. Add that.. But adding both when you only need one, has never and will never make sense to me.. I'd reduce the amount of part A or B that you're using (reduce whichever has the most calcium and magnesium in it). I hate saying it, but you goal now is to try to get to harvest.. It won't be cute, but there isn't much you can do to correct this at this point. It would literally take a soil test or lab test to tell us what nutrients are out of balance.. There's a thread in the mega crop section that is hundred of pages of exactly this kind of issue.. Everything looks fine in veg, then bam.. The roof gets blown off.. I hate when people get discouraged, so next grow, tag me or someone in the journal early on! I'll help as much as I can..

Aren't calcium and magnesium (along with iron) packaged together because it's important that they be fed in the correct ratio for nutrient uptake? I guess you could serve them up separately if careful and had a good understanding of the necessary ratios.

And do you grow under LEDs? You don't buy into the theory that LED growers may need to supplement with CalMag? Was just reading through this admittedly dated thread on that very subject: https://www.autoflower.org/threads/led-and-calmag-discussion.24451/

 

[Mañ'O'Green]

@TheCannaZombie When you feed the "Cal-Mag" is it an increase in the regular nutrient blend or are you putting it in the pot by itself?