Yellow spots and leaves curling and thin

[Uncle_Ruckus]

First post here.. so go easy on me lol.

Growing 2 Crown Royale plants, since seed starting in February - they've been doing great up until about 2-3 weeks ago, when I started noticing the leaves beginning to wilt on one, and the other beginning too. Now they're showing yellowing and in some cases the tips of the leaves actually breaking off.

I'm growing in Coco, using Advanced Nutrients with nothing else. I initially thought PH issue, so last night I decided to flush each 11 liter pot with 3.5 liters 5.8 ph'd rain water and got about 20% run off. I should have ph checked it, but didn't - will try tonight.

I'm using 4 QB132's for light btw.

I'm going to leave them be for about a week, and see how they respond... but just looking for any thoughts.

 

[Uncle_Ruckus]

Looking at the 1st image more... I wonder if this could be a calcium deficiency. Although I am using Sensi bloom for coco which should have me covered I'd think.

 

[Logan Burke]

When growing under LED's, it isn't uncommon for cannabis to require higher levels of calcium and magnesium than they otherwise would. I have never grown in coco before, so I really can't be of great help there. If you decide to apply the calmag, just watch closely to see if the symptoms continue to spread. If that is the issue and adding more cal/mag fixes it, then the existing symtpoms will not go away. They are permanent. You will realize it is getting better when the symptoms cease spreading to new leaves.

 

[Uncle_Ruckus]

When growing under LED's, it isn't uncommon for cannabis to require higher levels of calcium and magnesium than they otherwise would. I have never grown in coco before, so I really can't be of great help there. If you decide to apply the calmag, just watch closely to see if the symptoms continue to spread. If that is the issue and adding more cal/mag fixes it, then the existing symtpoms will not go away. They are permanent. You will realize it is getting better when the symptoms cease spreading to new leaves.

Thanks man,


I've just been reading up this afternoon on that fact exactly (LED's essentially robbing calcium and magnesium from the plant)... and also, where I'm using rain water, while I don't have a ppm meter or gauge I'm guessing its much lower than tap water would be... so another reason to try some calmag.

Gonna drop in to the local hydro store on the way home and may try some in a few days... right now it really shouldn't have any more waterings... lol.

 

[Logan Burke]

Yes I would say that is either the core of your issue or at the very least is acting as a pretty big antagonist, in either event getting that under control will really help to simplify things. Sounds like you've got a game plan put together, I hope everything goes well for you and your baby's, please update us if there is any further assistance we can provide.

 

[Tuckatan]

Thanks man,


I've just been reading up this afternoon on that fact exactly (LED's essentially robbing calcium and magnesium from the plant)... and also, where I'm using rain water, while I don't have a ppm meter or gauge I'm guessing its much lower than tap water would be... so another reason to try some calmag.

Gonna drop in to the local hydro store on the way home and may try some in a few days... right now it really shouldn't have any more waterings... lol.

I grow in coco with rain water, my rain water comes in at 35ppm, I use 2.5ml/gal of calmag every water with gh trio. Coco holds on to the Ca and Mg too so you should definitely add calmag.

 

[CannaCountry]

Your plant is a little short on Ca...which are the rust spots in your first pic. Your other pic suggests maybe the plants want a little more food (they're a smidge limey?) and it appears you may be short on Mg as well. As noted above, the LED's will certainly take their toll on Ca and Mg uptake, of course so will your coco. If it were me, I would try to impart them (Ca and Mg) individually to the plant, vs. the standard CalMag, but do what you have to do. Either way you appear as though you need both.

A few other pennies...

I'm not a big fan of 'flushing', in fact I think it's like the last ditch effort in most cases, never the less, if you're going to do it in a coco grow, don't flush with just plain water pH'd or not. Flush with a reduced feed, but never plain water...your plants won't like it and neither will your coco.

Can you elaborate on your feed schedule? I assume you feed every day, multiple times a day? Are you feeding full strength nutrients when you feed? Do you ever give them just plain water vs. water containing nutrients? Are you letting your plants dry out in between feeds? The devil is in the details...let us know.

 

[Jypsy Dog]

Grab the tips you need to get back on track from this guy... No Bull Shit, just CoCo..
https://cocoforcannabis.com/

 

[Uncle_Ruckus]

Your plant is a little short on Ca...which are the rust spots in your first pic. Your other pic suggests maybe the plants want a little more food (they're a smidge limey?) and it appears you may be short on Mg as well. As noted above, the LED's will certainly take their toll on Ca and Mg uptake, of course so will your coco. If it were me, I would try to impart them (Ca and Mg) individually to the plant, vs. the standard CalMag, but do what you have to do. Either way you appear as though you need both.

A few other pennies...

I'm not a big fan of 'flushing', in fact I think it's like the last ditch effort in most cases, never the less, if you're going to do it in a coco grow, don't flush with just plain water pH'd or not. Flush with a reduced feed, but never plain water...your plants won't like it and neither will your coco.

Can you elaborate on your feed schedule? I assume you feed every day, multiple times a day? Are you feeding full strength nutrients when you feed? Do you ever give them just plain water vs. water containing nutrients? Are you letting your plants dry out in between feeds? The devil is in the details...let us know.

Thanks very much for the advice,

I think you're probably right with regard to being short on Ca - and also on the lack of food too..

My feed schedule is not really a schedule - just basically water them when the pots feel light and the medium looks dried out. What that translates into is me watering with a 5L watering can, mixed with my nutrients, and usually 2.5L gets used every 2nd or 3rd day.

I'm using Sensi Grow part A and B, and PH to 5.8. I'm going to let them keep drying out a bit after their flush, and start using 1.5ml per L of CalMag once I water again.

Perhaps I also need to start watering less, but more frequently like twice per day - but I was under the impression this was not good practice - as nothing ever makes its way down to the lower roots.

Plants are not doing well at all as of today, and now noticing red, dried out stems / stalks.

 

[Corenugzz]

Thanks very much for the advice,

I think you're probably right with regard to being short on Ca - and also on the lack of food too..

My feed schedule is not really a schedule - just basically water them when the pots feel light and the medium looks dried out. What that translates into is me watering with a 5L watering can, mixed with my nutrients, and usually 2.5L gets used every 2nd or 3rd day.

I'm using Sensi Grow part A and B, and PH to 5.8. I'm going to let them keep drying out a bit after their flush, and start using 1.5ml per L of CalMag once I water again.

Perhaps I also need to start watering less, but more frequently like twice per day - but I was under the impression this was not good practice - as nothing ever makes its way down to the lower roots.

Plants are not doing well at all as of today, and now noticing red, dried out stems / stalks.

Be careful using cal-mag if u already have a high nitrogen I'd suggest using Epsom salt

 

[CannaCountry]

Thanks very much for the advice,

I think you're probably right with regard to being short on Ca - and also on the lack of food too..

My feed schedule is not really a schedule - just basically water them when the pots feel light and the medium looks dried out. What that translates into is me watering with a 5L watering can, mixed with my nutrients, and usually 2.5L gets used every 2nd or 3rd day.

I'm using Sensi Grow part A and B, and PH to 5.8. I'm going to let them keep drying out a bit after their flush, and start using 1.5ml per L of CalMag once I water again.

Perhaps I also need to start watering less, but more frequently like twice per day - but I was under the impression this was not good practice - as nothing ever makes its way down to the lower roots.

Plants are not doing well at all as of today, and now noticing red, dried out stems / stalks.

Don't let your plants dry out...in coco, they do not like this. You will be much better served keeping your coco always moist. This may very well be some of your issue. I would readjust my feedings so your coco stays moist over the entire day...lights on or off. Good luck.