Magnesium issues(?) wont cease

BJ1617

BJ1617

Well-Known Member
I have a girl showing signs of magnesium def. I'm following growweed easy's nute schedule which calls for 1/2 tsp of cal mag per gal since I'm at week 2 of flower. To try to fix it I went to 3/4 tsp per gal of cal mag and a tsp of dissolved epson salts and it's still climbing.
my water isn't hard im talking <100 ppm at tap. I moved the light from 16" to about 19" it is a 600 hps. I checked the roots which are pearly white. And I monitor the ph daily, just checked again when I took these pictures and it's sitting at 6. Temps are at most 77f. ppm is usually 800-ish but with the extra calmag and salts it comes to 940.
What can I do?
 

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CannaCountry

Well-Known Member
How are you growing style wise...what medium are you using? Have you been feeding Mg daily since the start? Have you sprayed any Epsom on them? Some of the leaf damage looks old. Has the Mg shortage been around a while? Have you researched your strain to see if it's inherently a heavy feeder of Mg? Just some questions that come to mind. Good luck.
 
Renfro

Renfro

Well-Known Member
xtsho said:
Magnesium is antagonistic with potassium. The OP has been adding a significant amount of magnesium.

Nutrient antagonism

Adding too much of one thing can cause issues with other things. Then you end up like a dog chasing its tail.

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Yeah that is a problem, I dunno how much K he has in his feed but just adding more mag when you already have enough isn't a fix at all.

Also his tap with unknown calcium content plus calmag and base nutes could provide another route for K antagonism.
 
BJ1617

BJ1617

Well-Known Member
@CannaCountry It's DWC, with hydroton and rapid rooter base, been feeding calmag since the start and haven't foliar fed them. signs have been going on for about 2 weeks now. The strain is girl scout cookies.

@Renfro It's been running about 5.5-6 but sometimes overnight it'll climb to 6.5-6.8

@xtsho So it looks like a potassium thing huh. Also just using standard GH trio btw, never had an issue with other strains grown using it so it must be strain-specific I'll look into it

Thanks for all the info guys
 
BJ1617

BJ1617

Well-Known Member
Also checked my current water report(attached) my cal is about 4.88 mg/l, my mag is 0.851 mg/l and potash is 0.978 mg/l. So I shouldn't supplement with calmag?
 

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BJ1617

BJ1617

Well-Known Member
Well based on my water report I'm already getting enough cal and will just get mag from nutes. Did a rez change and am sitting at a comfy ~600. It's weird because my previous grows of tangerine dream and pineapple chunk took the extra cal mag fine. But it definitely is a potash issue after looking into it. I'll update later and thanks again!
 
BJ1617

BJ1617

Well-Known Member
Well ive been adding calmag lately at .5 tsp/gal for 3.5 gal and it led to this. Ill just see if the base notes can handle this and hopefully stop the Potash lockout.
 
icetech

icetech

Well-Known Member
That's all PH issues... i used to have that problem below like 5.9 i started phing to 6.1 and plants are crazy healthy.. are you using a real pen or just drops?
If you look at the charts cal and mag uptake pretty much drop to nothing below 5.8-5.9.. and will look like deficiencies cause the plant is basically deficient at that point..

P.S. i would cut the nuts back to about 1.6ec (800ppm) and get the PH fixed and they will hopefully get healthy again.
hydroponics-ph-chart-marijuana.jpg
 
icetech

icetech

Well-Known Member
BJ1617 said:
@icetech I use drops. And the ph may be a factor also I typically ph to 5.5 and let it rise. I'll set it higher and stay vigilant. Thanks
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If you can spare the cash, pick up a Apera PH60 pen.. it's easily the best money i have spent on anything for growing.. no more guessing at ph with drops and i haven't had to calibrate it since the first time when i bought it.. well worth the money.
 
70's natureboy

70's natureboy

Well-Known Member
Apera ph60 huh? It sounds too good to be true but I may try one someday. That's why I replied, so I might find this post someday. thanks.

I think I tried a milwaukee and something else and they had me chasing my tail.

For the OP I think they are getting crispy and the ppms should be lower.
 
xtsho

xtsho

Well-Known Member
BJ1617 said:
@CannaCountry It's DWC, with hydroton and rapid rooter base, been feeding calmag since the start and haven't foliar fed them. signs have been going on for about 2 weeks now. The strain is girl scout cookies.

@Renfro It's been running about 5.5-6 but sometimes overnight it'll climb to 6.5-6.8

@xtsho So it looks like a potassium thing huh. Also just using standard GH trio btw, never had an issue with other strains grown using it so it must be strain-specific I'll look into it

Thanks for all the info guys
Click to expand...

I don't know what it is. I was just pointing out with that chart that adding more of one thing to fix a perceived deficiency can have other adverse effects on the plant. Some people dump too much stuff on their plants which causes the deficiency to begin with and then the solution is to add more of something when the proper solution is too cut back on something.

There's that chart of illustrations showing plant deficiencies many people go by. Before they do anything based on that chart they should always consult Mulders chart especially if they're adding any additives.
 
BJ1617

BJ1617

Well-Known Member
Im back wanted to give an update. It seems the girl(GSC) likes her ph a little high around 6.5. Made the change after the suggestion and she's stopped dropping top leaves. Here's a pic of her now. There's enough healthy ones left I feel to make a grand harvest. Thank you all once again.
:bigjoint:
 

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