11 day auto seedling with Ca def and N tox? What should I do please?

[elcoloan]

Good morning.
I come to you again this time with my second autoflowering run. It's a 24Carat x 3Bearsog from Mephisto. From day 4 she started showing Ca def: wavy leaves, and then brown spots. Symptoms increased, and since yesterday i noticed tips pointing downward a bit and today one is cleary in claw... so I feel it has an N tox. As soon as the Ca def spots showed I gave foliar Calmag at 250 ppm (0.5 conversion) every day and increased the calmag in the next watering by 20 ppms... but symptoms actually got worse. Even the little new growth today has a spot on it.

I'm using 100% coco in 2.2 Gal autopot under a quantum board style lamp with deep and far red, uv, etc (specs here) that can pull 120W but i use it down to 60W . Seedling was stretching too much at 36 inches from the light so i put her there at 30 inches and she stopped stretching and started increasing leaf size. A couple of days after this first spots appeared.

I buffered my coco following cocoforcannabis instructions before planting the seed in it... and after this, runoff with tap 70 ppm water after the buffering came out at 130 ppm aprox.
Then, following Bushamasterar15's schedule I precharged the coco with 400 ppm (250 MegaCrop1, 80 ppm CalMag Pro, 70 tap water), ph 6.0-6.2. Let it sit in the tent a few days to get it warmed up and the put my germinated seed in there.
Then at day 5 i gave a 500 ml watering with nutes at 420 ppm and 6.4 pH (250 MegaCrop1, 100 ppm CalMag Pro, 70 tap water) increased Calmag by 20 ppm since the Ca def spot showed up the day before. Spots kept appearing and yesterday was day 10 and I watered again with the same EC as day 5 with pH 6.2, but this time with 750 ml. A few hours later i saw tips of leaves kind pointing down and today one of the leaves is clearly clawing. I stopped the foliar CalMag a couple days ago. Next watering is supposed to be on day 15 with same EC nutes.

Temp have been 20-27 C, and RH has been around 40% during the night, and close to 35% at day in average but a few days ago i was able to get it to increase to 50% during the day and 60% during the night.

So, what would you do? what would your diagnosis be, please?
I imagine the low RH can be causing the Ca def (don't remember where i read that) and since VPD is out of range, that's why I sought to increase the RH. But seeing the possible N tox, I'm also wondering if too much CalMag Pro ended up increasing N so much that it's blocking Ca. Other than increasing the RH, not sure what else to do... maybe give just pHed tap water (with bennies -og biowar root pack- could be an option) to lower the EC in the coco? or just wait and let it adapt? A friend pointed out I might have began counting days too early... maybe I gave the watering too son and she still needed to grow a bit more?

Here are some pics for better reference:

DAY 1

DAY 11 (today)

 

[blue]

So, what would you do? what would your diagnosis be, please?

Heya!

I don't think i can fix your issues, but can say that N Tox is manifested with dark green leaves that claw down (so it's probably not that).
It looks like you've done the right thing with the feed.

I'd be looking for either Bugs .. or the PH range takeup (i've always shot for lower than you've been PHing in coco).

I can try and call in a coco pro @St. Tom (keeping you busy with the coco threads! )

Hopefully this will get you a bump and some more eyes on the issue.
Other than the spots, she's looking okay for an 11 day seedling.

 

[St. Tom]

hi @elcoloan i use pre buffered coco so im not sure about buffering it yourself but id say your correct about the calmag issue in the begging and if i was you i would of sprayed her once being so small and just upped your calmag in your feed and just concentrate on the new growth as the spotted leaves wont look much prettier that's why i say just about the new growth also i can assume @bushmasterar15 will be able to help you further when he logs on but here's my go to guy @Arthur also growbro i would start now by next feeding measure your run off see whats your coco is holding to what your putting in

 

[elcoloan]

Heya!

I don't think i can fix your issues, but can say that N Tox is manifested with dark green leaves that claw down (so it's probably not that).
It looks like you've done the right thing with the feed.

Heya!

I don't think i can fix your issues, but can say that N Tox is manifested with dark green leaves that claw down (so it's probably not that).
It looks like you've done the right thing with the feed.

I'd be looking for either Bugs .. or the PH range takeup (i've always shot for lower than you've been PHing in coco).

I can try and call in a coco pro @St. Tom (keeping you busy with the coco threads! )

Hopefully this will get you a bump and some more eyes on the issue.
Other than the spots, she's looking okay for an 11 day seedling.

I'd be looking for either Bugs .. or the PH range takeup (i've always shot for lower than you've been PHing in coco).

I can try and call in a coco pro @St. Tom (keeping you busy with the coco threads! )

Hopefully this will get you a bump and some more eyes on the issue.
Other than the spots, she's looking okay for an 11 day seedling.

Thanks for the quick response and input!
Good point on the N tox... so maybe just waterlogged? I also find it peculiar how it's really just one leaf and on the same side as one ofthe cotys that is also bent. And on on previous runs with coco I used closer to 5.8-6.0 pH, but got Mg def so wanted to try going higher this time... maybe i should stay closer to 6.0. Again, thank you for the input!

hi @elcoloan i use pre buffered coco so im not sure about buffering it yourself but id say your correct about the calmag issue in the begging and if i was you i would of sprayed her once being so small and just upped your calmag in your feed and just concentrate on the new growth as the spotted leaves wont look much prettier that's why i say just about the new growth also i can assume @bushmasterar15 will be able to help you further when he logs on but here's my go to guy @Arthur also growbro i would start now by next feeding measure your run off see whats your coco is holding to what your putting in

Ok, will try to get runoff next time. I was intending on it last time but i didn't get a single drop since I'm trying to avoid root rot this run from overwatering... will try with 1Lt next time to get soem runoff readings. Thanks so much!

 

[Proph]

2+2 is 4.. Don't over think things.. You've added several sources of calcium to the coco.. You buffered the coco.. You've sprayed the plant with calmag.. And you're thinking it's a calcium deficiency at 11 days old. Don't over think it.. You know it's not calcium deficient because you've given it multiple calcium sources and even sprayed it.. We know by your description that there is more than enough calcium in the coco. We also know that coco is excellent at retaining nutrients and the cation exchange should have happened when you buffered it.

Signs of deficiencies do not automatically mean add more! I can't stress that enough. Always keep that in mind.. Especially with young plants/seedlings.. More often than not, the signs of deficiency are caused by a nutrient lock out. You don't need to add cal mag this early on in pre buffered coco.. It's pre buffered with calcium and magnesiun (or should have been).. Keep in mind that "calmag" is two nutrients.. Too much calcium will lock out magnesium (and other nutrients), making it unavailable to the plant.. Too much magnesium will lock out calcium (and other nutrients), making it unavailable to the plant. Im pretty sure that's what happened. Too much of one, locked out the other. You want to watch the new growth and make sure the leaves look healthy and that the rust spots aren't spreading. Young plants don't need much of anything. They will feed themselves through the cotyledons until their roots are established. I'd back off all the cal mag, or read up on its use if you feel you have to use it. Id say you have a lock out already due to excess calcium.

450 ppms is a lot for a seedling. When I was using bottles, I never went over 650 ppms. Even in flower. 400ppms is more for mid veg, not a seedling. Im also not sure how you buffered the coco, but have a run off of 130ppms. The cocoforcannabis buffering instructions say to buffer the coco with a 1200ppm solution of calmag.. I don't understand how it does from 1200 to 130ppms in a rinse.

I know it's a lot... But these are all things that must be learned or understood at some point in order to grow successfully in coco. Coco leaves zero room for error. You have to be on your A game at all times or things can go haywire overnight.

 

[elcoloan]

2+2 is 4.. Don't over think things.. You've added several sources of calcium to the coco.. You buffered the coco.. You've sprayed the plant with calmag.. And you're thinking it's a calcium deficiency at 11 days old. Don't over think it.. You know it's not calcium deficient because you've given it multiple calcium sources and even sprayed it.. We know by your description that there is more than enough calcium in the coco. We also know that coco is excellent at retaining nutrients and the cation exchange should have happened when you buffered it.

Signs of deficiencies do not automatically mean add more! I can't stress that enough. Always keep that in mind.. Especially with young plants/seedlings.. More often than not, the signs of deficiency are caused by a nutrient lock out. You don't need to add cal mag this early on in pre buffered coco.. It's pre buffered with calcium and magnesiun (or should have been).. Keep in mind that "calmag" is two nutrients.. Too much calcium will lock out magnesium (and other nutrients), making it unavailable to the plant.. Too much magnesium will lock out calcium (and other nutrients), making it unavailable to the plant. Im pretty sure that's what happened. Too much of one, locked out the other. You want to watch the new growth and make sure the leaves look healthy and that the rust spots aren't spreading. Young plants don't need much of anything. They will feed themselves through the cotyledons until their roots are established. I'd back off all the cal mag, or read up on its use if you feel you have to use it. Id say you have a lock out already due to excess calcium.

450 ppms is a lot for a seedling. When I was using bottles, I never went over 650 ppms. Even in flower. 400ppms is more for mid veg, not a seedling. Im also not sure how you buffered the coco, but have a run off of 130ppms. The cocoforcannabis buffering instructions say to buffer the coco with a 1200ppm solution of calmag.. I don't understand how it does from 1200 to 130ppms in a rinse.

I know it's a lot... But these are all things that must be learned or understood at some point in order to grow successfully in coco. Coco leaves zero room for error. You have to be on your A game at all times or things can go haywire overnight.

Thanks! I've had some pH problem and root rot issues en previous runs so I know i have to bee in my A game to have healthy plants in coco. I did get sloppy with the low RH this run and was aware I was starting with a much higher EC than I would have before...
On my previous runs I only used to use a maximum of 320 ppm total to fertigate (200-250 ppm MegaCrop v1 + 50-70 ppm tap) for watering seedlings, but wanted this time around to try bushamarterar15's sched which might actually be over my 400 ppms in total since it includes Sugar Candy and other things I'm not using... but of MC im using the same amount as that sched and of CalMag I even began with lower and only increased up to the scheds amount when i saw the first spots... but i guess my 70 ppm of tap added more than i thought and i did also add the foilar calmag everyday after seing the first spots (following cocoforcannabis site) but at the same time felt it made things worse... but i even tried half the strength thats recommended for seedling foliar so I didn't think it would be that bad but yeah it felt wrong anyways. Had never given nutes with foliar spays... learnt my lesson there.
Anyhow, I was hoping it would adapt and ride it out but maybe I should go back to using lower EC as before but still keep on track with bushamasterar15's sched while making sure to lower or even remove the CalMag out of the equation.

Oh by the way, about the buffering resulting in low EC the coco guy also mentions this a few steps ahead in the instructions: "Fill the container you will be using with coco/perlite and add water slowly until you can collect run-off. Measure the EC of the first run-off water to leave the pot and confirm that it is in the appropriate range for seedlings (less than 400 or 0.4 EC) or vegetating plants (less than 1000 or 1.0 EC). If the EC is high, continue pouring plain water through the pot until run-off readings are in the appropriate range. After rinsing the EC down like this, it is a good practice to then fertigate (add water with fertilizers) at the appropriate EC prior to adding plants." Since my tap is 70 ppm, i thought that kinda somehow made sense that after i continued pouring more tap, it continued decreasing. But you and the coco guy agree, the EC i precharged at is double what the coco guy says.. lucky how others manage to get through with those high ECs.

 

[bushmasterar15]

What has worked for me might not for others. I don't use a PH or TDS pens, just plain well water mixed with nutes and just try to keep an eye on how
things go. Sometimes if you overthink it then you start chasing problems.

 

[elcoloan]

What has worked for me might not for others...

I hope I can adjust it to work for me... looks so simple!

 

[Proph]

I hope I can adjust it to work for me... looks so simple!

My old friend Bush is correct. What works for him, may not work for you. Remember, you're growing a plant, not building a bird house. There is no schedule, or set of instructions that will get you a promised result. There is no guaranteed blue print. Every plant is different. Some are heavy feeders, some are light feeders, some are sensitive to certain nutrients, some are sensitive to light levels... So are fast growers/ finishers... Some are slow.. You should be feeding and caring for the plant based on its needs. I know it's tough for new growers to do, but that has to happen at some point! As for now. I would just watch the new growth for now and cut back on the calmag. Also, keep in mind that almost every set of instructions you read about cannabis online, is talking about growing photo period plants and are based on a standard 4 week veg cycle. 4 weeks of an auto and it's in the start of flower. So that's to be considered as well.

 

[Mañ'O'Green]

It would be my guess that low RH is the cause of the first spots. If the stomata of the plant are closed to preserve moisture the plant stops respiring which means it cannot carry any calcium into a rapidly growing plant. This mimics a deficiency even though plenty of calcium is available in the coco. In a true defieincy 50 PPM in a single foliar application is plenty done no more often than once a week.