Calcium Deficiency? (Photos)

Hello everyone. I've got a couple photos attached of what I'm seeing that I think is pretty clearly calcium deficiency. I have heard pottasium overdose can look like calcium deficiency as well though so it could possibly be that and I was wondering what people think.

I'm confused as to how I could even have a calcium deficiency. I use 3 mL cali-magic (cal mag) every watering and I'm using tap water. So I feel like there should be plenty of Calcium in there. Should I up it to 3.5 mL cali magic?
Bloom fertillizer is at 3.0 mL per gallon so I am using a bit higher potassium nute soln but they are in day 40 flowering so Im pretty sure im supposed to be doing that.
I get pH to 5.8-6.0 every time with a meter (ATC calibratible). Calcium absorbs best in hydro at 6.2-6.5 I guess, so maybe I should do a watering at pH 6.2 next time?

I'm not sure what the best route to go around fixing this is. Any advice is greatly appreciated!
View attachment 3621015View attachment 3621014
Also the top leaves are the only ones really showing this issue.

Other info:
-water about every 4 days, 1 gal tot
-using GH flora trio plus cali magic
-under 400W hps about 17 inches away
-NYCD is the strain
-40 days into flower, estimated 72 days flower till harvest for NYCD.
-temp is about 68 at night and 78 in day
Anything else just ask

Despite this minor issue the buds are looking great! I went out of town for 4 days and came back to them looking denser than ever! So they're really starting to fill out. Stuffed with trichomes.


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As a general rule I like 5.5-5.8 ,in veg and 5.8-6.3 in flower.

It helps pick up all those important flowering nutrients without leaving out some important micros.

If you are using a resivoir,sometimes a little ph swing is a good thing.If you are hand feeding,vary the ph across those ranges.

what are your ppms or ec

Resinhound said:

As a general rule I like 5.5-5.8 ,in veg and 5.8-6.3 in flower.

It helps pick up all those important flowering nutrients without leaving out some important micros.

If you are using a resivoir,sometimes a little ph swing is a good thing.If you are hand feeding,vary the ph across those ranges.

Click to expand...

Im growing in coco coir. Sorry, I forgot to mention that.
So should I do a watering at 6.2 ish like every 3 waterings or so? (Starting the next)
Does that sound like a good plan?

Sent from my SGH-M919 using Rollitup mobile app

Ya mix it up ...dont feed the same ph everytime.Mix it up between 5.8-6.2, over the course of the grow this should give you maximum nutrient absorbsion.

I wouldnt use a regimented plan,just swing it around a.bit from feed to feed.

Its important to realize coco will sequester calcium and magnesium,and release potassium.So make sure you are adding some extra cal and mag.Take it easy on potassium supplements,that can further aggrivate the mag situation in coco.