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

[pg2052]

So, I am on my 4th plant now that has the same issue. Brown spots on the upper leaves. I have flushed, still progresses. I have added calmag, still progresses. I am in coco/perlite 70/30. Megacrop 2 Part. PH is always 5.8-6.2 depending on the stage. Never above 550ppm, usually just 500-525. I have only ever noticed this when flowering but it start almost immediately after stretch. Please see the pics and let me know what you think. First two pics are from the oldest and the next two are her younger sister. I am willing to try anything short of setting my tent on fire. TIA!
View attachment 1301931View attachment 1301932View attachment 1301933View attachment 1301935

I've had the same exact issues on multiple plants indoors. I'm a very new grower, but I can tell you what worked for me recently. I wasn't using any CalMag at all (other than just what's in my 140ish PPM tap), but as soon as I started seeing those classic rust spots on the top of my canopy (right around preflowering, when it always seems to happen to me), I bought some SaferGro Biomin Calcium and gave my troubled plant one good dousing via foliar spray and the problem stopped dead in it's tracks -- and when I've had that problem creep up in the past, it's never stopped in its tracks...it just keeps growing and spreading inevitably no matter what I do and eventuallly gets into the sugar leaves and sucks. This was 3 weeks or so ago, and maybe it'll start creeping back at some point, but if it that foliar spray bought me a month or more of time, then that's ok by me. Unfortunately I didn't spray my other 2 plants because they were growing so nicely I didn't want to f them up (the one I sprayed was a runt that I figured I'd just toy with a bit) -- and now my 2 nice looking plants are covered in rust spots and my little runt is as green as can be. Not sure whether you can still foliar spray at this point, but might be worth a shot at some point down the road. Again, I'm a new grower, so take all of this with a giant grain of salt...just sharing my experience.

 

[TheCannaZombie]

@Mañ'O'Green It is in addition to the nutrients. I mix the calmag first. Then add in the A, then the B.

@pg2052 Thank you for the input. I have never looked into foliar sprays, but I will be checking it out.

 

[Proph]

I've had the same exact issues on multiple plants indoors. I'm a very new grower, but I can tell you what worked for me recently. I wasn't using any CalMag at all (other than just what's in my 140ish PPM tap), but as soon as I started seeing those classic rust spots on the top of my canopy (right around preflowering, when it always seems to happen to me), I bought some SaferGro Biomin Calcium and gave my troubled plant one good dousing via foliar spray and the problem stopped dead in it's tracks -- and when I've had that problem creep up in the past, it's never stopped in its tracks...it just keeps growing and spreading inevitably no matter what I do and eventuallly gets into the sugar leaves and sucks. This was 3 weeks or so ago, and maybe it'll start creeping back at some point, but if it that foliar spray bought me a month or more of time, then that's ok by me. Unfortunately I didn't spray my other 2 plants because they were growing so nicely I didn't want to f them up (the one I sprayed was a runt that I figured I'd just toy with a bit) -- and now my 2 nice looking plants are covered in rust spots and my little runt is as green as can be. Not sure whether you can still foliar spray at this point, but might be worth a shot at some point down the road. Again, I'm a new grower, so take all of this with a giant grain of salt...just sharing my experience.

Just remember.. Foliar Spray can't resolve or fix issues though... Especially not a Calcium issue. Calcium is immobile, so a foliar is like a band-aide. Also keep in mind that it's not just cal mag that's at play.. The 2 part MC has way more than enough calcium and magnesium in it. I remember when they changed the formula from almost none, to too much of both.. These are pics from the MC website..

Part B has 19% calcium!!! That's more than phosphorus, which is a primary nutrient!! Again, calcium is a secondary nutrient. It's not constantly needed.. At all.. Then there's the calcium the coco was buffered in.. And the calcium the recharge is releasing. It's not just one source.

 

[Proph]

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/

No.. If that were the case "calmag" would have been around 20 yrs ago.. I don't buy into much, I prefer to follow science and nature. Calcium and magnesium are two entirely different nutrients that react differently and that have issues that are treated differently. Calcium is immobile.. Magnesium is mobile. Too much of one cancels out the other.. So If you have a calcium issue, how would adding magnesium help resolve it? If you search this site, you'll find threads that say don't top your plants, don't transplant your plants.. Threads that say you can't clone autos etc.. People are going ti believe what they want. So if someone wants to believe that LEDs cause your plant to use more calcium.. And that adding both calcium and magnesium is the solution, then so be it. If people understood why that even became a discussion, they'd know adding calcium or magnesium isn't the true answer.. Raising the temp in the environment is all that's needed. Everyone learns at their own pace and in their own way. Once you really get into it, you'll learn the same for yourself.

 

[pg2052]

No.. If that were the case "calmag" would have been around 20 yrs ago.. I don't buy into much, I prefer to follow science and nature. Calcium and magnesium are two entirely different nutrients that react differently and that have issues that are treated differently. Calcium is immobile.. Magnesium is mobile. Too much of one cancels out the other.. So If you have a calcium issue, how would adding magnesium help resolve it? If you search this site, you'll find threads that say don't top your plants, don't transplant your plants.. Threads that say you can't clone autos etc.. People are going ti believe what they want. So if someone wants to believe that LEDs cause your plant to use more calcium.. And that adding both calcium and magnesium is the solution, then so be it. If people understood why that even became a discussion, they'd know adding calcium or magnesium isn't the true answer.. Raising the temp in the environment is all that's needed. Everyone learns at their own pace and in their own way. Once you really get into it, you'll learn the same for yourself.

There are lots of agricultural studies out there concerning the interplay of those two micros -- it's not just a weed forum phenomenon. But you're right, if you have a calcium issue, the magnesium isn't going to help you correct that issue -- but feeding the calcium alone could result in magnesium deficiencies, hence the packaging (at least that's my understanding). And sure CalMag in a bottle with a colorful picture of some rastafarian on the label may be a new canna-specific marketing development, but weed growers ain't the reason they tossed those two nutrients in the same colorful bottle. Heck farmers have been using dolomitic limestone on their crops for centuries. I'm sure you're right that it's an overused bottle in general, but I just have a really hard time believing that there is no "science and nature" to support them being fed together in certain ratios.

And I agree that there is obviously tons of misinformation out there, and it's very difficult to sift through it and figure out what is what, but when someone like TaNg starts a thread about the need for CalMag supplementation under high-powered LEDs, I tend to tune in and hear what he's got to say.

 

[Mañ'O'Green]

There are lots of agricultural studies out there concerning the interplay of those two micros -- it's not just a weed forum phenomenon. But you're right, if you have a calcium issue, the magnesium isn't going to help you correct that issue -- but feeding the calcium alone could result in magnesium deficiencies, hence the packaging (at least that's my understanding). And sure CalMag in a bottle with a colorful picture of some rastafarian on the label may be a new canna-specific marketing development, but weed growers ain't the reason they tossed those two nutrients in the same colorful bottle. Heck farmers have been using dolomitic limestone on their crops for centuries. I'm sure you're right that it's an overused bottle in general, but I just have a really hard time believing that there is no "science and nature" to support them being fed together in certain ratios.

And I agree that there is obviously tons of misinformation out there, and it's very difficult to sift through it and figure out what is what, but when someone like TaNg starts a thread about the need for CalMag supplementation under high-powered LEDs, I tend to tune in and hear what he's got to say.

The Cal-mag thing started with cheap coco that had to be washed and pre-charged. Then stoners being stoners just decided if it is good there it must be good everywhere.

IMPO what people observed with LEDs was a rapid growth that outpaced the nutrients in the pot and the Bro-science took over.

Well watch out Bro-science I am getting lab equipment that if I learn to use correctly will put and end to this guess work. I will be able to test nutrients and Plant sap for N, P, K, Ca

 

[Proph]

There are lots of agricultural studies out there concerning the interplay of those two micros -- it's not just a weed forum phenomenon. But you're right, if you have a calcium issue, the magnesium isn't going to help you correct that issue -- but feeding the calcium alone could result in magnesium deficiencies, hence the packaging (at least that's my understanding). And sure CalMag in a bottle with a colorful picture of some rastafarian on the label may be a new canna-specific marketing development, but weed growers ain't the reason they tossed those two nutrients in the same colorful bottle. Heck farmers have been using dolomitic limestone on their crops for centuries. I'm sure you're right that it's an overused bottle in general, but I just have a really hard time believing that there is no "science and nature" to support them being fed together in certain ratios.

And I agree that there is obviously tons of misinformation out there, and it's very difficult to sift through it and figure out what is what, but when someone like TaNg starts a thread about the need for CalMag supplementation under high-powered LEDs, I tend to tune in and hear what he's got to say.

Any nutrient mix can be applied in the proper ratios.. Yes, other farmers use calcium and magnesium. Point me to ANY farmer using calmag.. Some crops use calcium as a primary nutrient. Cannabis doesn't. Feeding any one nutrient alone can cause an imbalance. Dolomitic lime isn't calmag.. Can't really compare the two.. Yes they both have calcium and magnesium.. But they are used is opposite ways for different purposes.. Dolomitic lime is used on outdoor gardens to help reduce acids in the soil.. It's also a dry amendment, which means it's usually not immediately available. No one is adding dolomitic lime to their bagged soils used indoors in 5 gallon pots.. Calmag is a cheated liquid feed that does nothing to reduce acids in the soil.. I will never try to change anyone's mind. Gardening is gardening. It's not really opinion based. But just to clear up the "science" behind the whole calmag/led thing, here it is... The concept came about as leds hit the scene.. Hps puts out more heat.. More heat means more transpiration. More transpiration means better calcium and magnesium movement through the water. Leds produce less heat... Less heat means less transportation.. Less transpiration means less calcium and magnesium movement through the water... That's the science. Straight up.. One day, some grower somewhere decided that since they use leds, and leds use less heat, and their plants will transpire less, causing less ca and mg circulation, then their plant will need more calcium and magnesium to make up for it.. And here we are today... But transpiration can easily be controlled by the environment.. That's what those VPD charts people keep sharing are all about, getting optimal transpiration.. Thus proper calcium and magnesium flow within the water.. There has never been, and never will be, a "need" to add calmag because your grow lights are leds.. Listen to and follow who ever you like! I support that.. All I ask is that you don't believe everything people type.. Not me, not Tang, not Son of Hobbes, not anyone, lol.. If it's true, it can be proven with a little research.. I support fact checking everything I type.. The proper info is out there for those that seek it. It's gardening 101.

 

[Builder0101]

Had similar looking issues with a different line of nutes (not salt based, but calcium based) turned out it was an alkalinity issue with RO water. Seems it needs a bit of re-mineralization before use, even with all the stuff we / I normally add.
The nutrient company recommended an add on for the RO system, but I've just been mixing ro and tap at a 4 to 1 ratio. At 100ppm mix, the problems have disappeared.

I always add a quart of my 550 ppm tap to my RO. NEVER water with RO only. IMO

 

[Builder0101]

"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..

THERE IS NO SUCH THING AS CALMAG. THERE IS CALCIUM AND THERE IS MAGNESIUM!!!
I laugh my ass off over CalMag. A friend if mine and I blame all of life's issues on calmag. One of these days I will get kicked off of this site for giving people shit when they suggest calmag.

 

[Arthur]

I always add a quart of my 550 ppm tap to my RO. NEVER water with RO only. IMO

Even mixed... I run feed feed feed feed. No water days. Still run into alkalinity issues if I don't mix.