Help with Deficiency n Coco + pics

I am having a strange issue uwith one of my blackjack plants 2 weeks into flower. Currently it looks like I am starting to have a deficiency on the lower leaves of this plant and the one next to it. The strange thing is of 2 identical plants one has yellow tips on upper fans and new growth. It looks kind of like burn but the other shows no signs of burn. They both display leaves as seen in pics. I can't figure out which way to go. Am I feeding too little or too much?
I am growing in a coco/perlite mix with some dolomite added for my medium. 1000w hps lamp and temps are 83 day and 70 at night and rh 45-50%. I am supplementing with co2 at 1500 ppm. I am feeding dyna-gro nutrients about .8 EC at 5.8 ph currently. I was running up to 1.2 EC but saw a little hooking and slight burn but these tips still look the same after dropping to .8. I use the bloom, magpro and protek at 5 ml 3 ml and 2 ml respectively. This is top feed to waste and res temp is 66 degrees always.
I will post better pics after lights out but I think the lower fan problem is pretty clear in the pics. The tops not so much.

Lower fan issues?

This one may be just because it is so buried?

Hard to see but one looks like burnt tips and the other looks fine?


I have a full journal of this grow in my signature as well. The Super Skunks I have going look fine so far.

So, I found this and it makes sense. My tips are lime green and really don't look burnt. I have heard of mag issues in coco so maybe this is it? I will get good pics of tips shortly at lights out.

Secondary Nutrients Magnesium (Mg) is found as a central atom in the chlorophyll molecule and is essential to the absorption of light energy. Magnesium aids in the utilization of nutrients, neutralizes acids and toxic compounds produced by the plant. Deficiency signs of magnesium are: Older leaves yellow from the center outward, while veins remain green on deficient plants. Leaf tips and edges may discolor and curl upward. Growing tips turn lime green if the deficiency progresses to the top of the plant.

Here is the affected plant. The tips are definitely lime green and looking closely I don't think it is burn? They aren't yellow like nute burn that I have seen in the past. I also see no clawing or other signs of over fert. The last pic is of another blackjack in the exact same conditions, feed schedule etc. Any thoughts?

it looks like a mix of things i would flush with a super light feed and maybe bump up the calmag if you are using ro water! Hope this helps and good luck bro!

Thanks! Yeah, I am running RO. I will flush and bump the cal mag. I may try some Epsom foliar too just to be sure. Anyone else want to chime in?

i'm currently having the same problem as you.Your situation looks a little bit more progressed than mine . Your first pictures show signs of stress on the leaf "tip" and the (margins,(sides of leafs)) to me that is early signs of K deficincey. If you google it you will see. Your later pics i don't see the leaf margins burning , i just see the tips burning.

I run Sphagnum peat moss, which is very similar and my ph is at 6.4 . although i can't really pin point your problem, because i'm not a pro :/ ( and i don't want to feed you some bullshit answer) i will tell you that you could easily flush your plant with a flushing solution and continue your regiment..

I don't think that you have any problems here. Lower leaves start to look weird with age, and the yellow tips are nothing to worry about. I would not change anything.

Sweet, thanks for the help. I think I will flush tomorrow with 50% strength nutes then just go back to feeding at .8 EC. I agree the lower leaves are not a big deal. The tips are what was freaking me out. I may add a little more mag pro to be safe as well. If anyone else has any opinions kick em in.

yellow tips are not a big deal? Obviously you don't listen to your plant

jpill said:

i'm currently having the same problem as you.Your situation looks a little bit more progressed than mine . Your first pictures show signs of stress on the leaf "tip" and the (margins,(sides of leafs)) to me that is early signs of K deficincey. If you google it you will see. Your later pics i don't see the leaf margins burning , i just see the tips burning.

I run Sphagnum peat moss, which is very similar and my ph is at 6.4 . although i can't really pin point your problem, because i'm not a pro :/ ( and i don't want to feed you some bullshit answer) i will tell you that you could easily flush your plant with a flushing solution and continue your regiment..

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Jpill, this looks right on. I looked at th k deficiency and you are correct. That really helps me get some direction. Maybe salt buildup etc. locking out. I will do the flush tomorrow and see if i can get back on track. I am going to leave mag pro at 3ml but up protek to 4ml since it has lots of k if the issue continues after flushing man, thanks again everyone for your help!!!

toss in some gardenlime

JoeCa1i said:

toss in some gardenlime

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I do have 1 tbsp dolomite per gallon of coco

here , save this to your desk top and refer to it when you need. It could be tht, cal mag, over fert. ph being off. It could be soo many diff things. sometimes it might just be you ph being off and that causes nutrients to be locked out or un useable.

http://growweedeasy.com/marijuana-symptoms

jpill said:

here , save this to your desk top and refer to it when you need. It could be tht, cal mag, over fert. ph being off. It could be soo many diff things. sometimes it might just be you ph being off and that causes nutrients to be locked out or un useable.

http://growweedeasy.com/marijuana-symptoms

Click to expand...

Thanks, that is tehe best I have seen. Most are really vague and no pics. It may just be as simple as flushing to make sure the ph is straight in the medium. I will start there and see how they respond rather than trying to address multiple theories. Thanks!

I flushed this morning with 200 ppm/ .4 EC nutrient solution at 5.8 ph. I will start feeding them at .8 EC tomorrow again. Looks like maybe ph off due to salt buildup in the coco possibly. I will post as soon as I see (or don't see) some results. Thanks for everyones help so far!

if you can find a ph chart you for cannabis it will tell you at what PH nutrients can start to be locked out !

Yeah, I looked at those and 5.8 looks ok but maybe 6 might be better for mg. this is my first coco run so I am not positive. Everyone I see running it says 5.8. I am hoping there was just salt buildup throwing the ph off in the coco but we will see I really appreciate your help on this!

np dude, just listen to the plant (like your doing) and you'll be fine. i've been doing this on and off since 09' and im still learning. If you learn about the nutrients you will have a very good understanding of cannabis growing early in your career. !

Sweet, I have used this ( http://www.growell.co.uk/blog/2011/04/talking-to-your-plants-part-1-body-language/ ) alot and man does it help get me in the zone. Also, I have been following uncle bens moisture stress thread too. We'll see how they respond over the next couple days

hey lookin for some help guys i have plants in coco and sum seem to b drinking and others not have you any idea what could be wrong? the ones drinking are deff getting faster bud growth than the ones that dont seem to be taking as much! any help would be greatfull