Cal mag def?

KebinLub

KebinLub

Member
Grown in canna coco
Day 16 flower.
Blue planet nutrients
Hlg led lights
Ph 6.2
Temps from 75 to 83
Humidity around 60 (dehumidifier is on the way)

Noticed some brown/dark spots on some of the leaves.Cal mag? I do add calmag to my res normally. Any help would be greatly appreciated. Thanks20200623_210201.jpg20200623_210316.jpg20200623_210145.jpg
 
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KebinLub

KebinLub

Member
Renfro said:
Your root zone pH is off or you have been experiencing wild pH swings.
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Thanks for the feedback. Checked my runoff about 4 days ago and it was 6.2. I'll check it again tommorrow and recalibrate my apera ph meter. Was thinking it might be phosphorus deficiency or cal mag.
 
Renfro

Renfro

Well-Known Member
KebinLub said:
Thanks for the feedback. Checked my runoff about 4 days ago and it was 6.2. I'll check it again tommorrow and recalibrate my apera ph meter. Was thinking it might be phosphorus deficiency or cal mag.
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Well that "stripey" pattern typically indicates a pH issue. I have seen it happen if they get a whack pH on one feed and I have seen the medium drift and get out of range when running soil, coco, peat based mix. A runoff test isn't always reliable. For example you may feed at 6.5, get runoff at 6.2 and the medium (root zone) is really at 5.5.

One thing too is a low pH can lock out magnesium.
 
KebinLub

KebinLub

Member
Renfro said:
Well that "stripey" pattern typically indicates a pH issue. I have seen it happen if they get a whack pH on one feed and I have seen the medium drift and get out of range when running soil, coco, peat based mix. A runoff test isn't always reliable. For example you may feed at 6.5, get runoff at 6.2 and the medium (root zone) is really at 5.5.

One thing too is a low pH can lock out magnesium.
Click to expand...
You think I should buy a ph reader for soil to get a more accurate reading?
 
TintEastwood

TintEastwood

Well-Known Member
Destroyer of chairs said:
Is that chart accurate? Cause this chart and several others say u need lower pH to fix Ca def?
View attachment 4604524
Assuming ur doing hydro cause of coco nutes
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For coco 5.8 thru 6.2 is very common. The charts can vary for sure.

nutrition-figure-1_fmt.png

I feed the range of 5.8 thru 6.3.
Too low Ca/Mg issues.
Too high P suffers.
Fun with coco.


Been here done this on past grow....a result of overcorrecting for ca/mg def. And too much K in my nutes.
potassium-excess-in-a-cannabis-plant-e1568202330791.jpg
 
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