Is this just a textbook, run-of-the-mill CalMag issue?

[Waira]

..yeah Rip, Mn defc. is weird, and poorly documented,.. but typically it looks like this->

... doesn't hit the veins, and causes more widespread yellowing,...

 

[Ripper]

Well that sure is an odd cal mg deficiency

 

[Waira]

...no Mg defc. here, just Ca,... it's common for them to occur simultaneously though, and it's no coincidence that the two are paired in together in supplements!

 

[Yozhik]

do you know what ppm's or EC the tap is at?

Yesterday prior to feeding I recalibrated the Bluelab Combo pH meter, to make sure I was getting the feed correct, as was suggested to do earlier in the thread.

Tap water - yesterday - EC was 0.5, with pH of 7.6.
It usually runs around 0.6 [+/- 0.1] and pH 8.0 [+/- 0/4], so it was within anticipated margins.

Oh-- also noted, and maybe it's just the camera/pics, but the plants look rather deep green, a minor sign of N-toxicity, which can mess with Ca uptake as well,...

Yeah - I was wondering about this.
Some of the girls are almost a lush, darker, British racing green hue, rather than the lighter, iridescent type green of the others.
In my head the little voices were starting to whisper the words "nutrient toxicity", as I have read a dark green may indicate.


EDIT:

As a footnote, I need to state ... my photography skills SUCK!
I really do need to put in some time and effort to correct this.

MEMO TO: Self
RE: Photos
Must search the forum for a 'photography' section, or a 'How To Take Killer Photos' guide.​

The photos are either too HPS affected, or too dark - the lighting is just ... wrong.
End result is I'm never able to capture the true colours of the plant, that I see with the naked eye.

So @Waira - to be fair - I don't make the diagnosis easy, 'cos I'm not sure you ever get to see the ACTUAL plant condition. My apologies.

 

[Ripper]

...no Mg defc. here, just Ca,... it's common for them to occur simultaneously though, and it's no coincidence that the two are paired in together in supplements!

Thank you sir.. I learned something and that is always a good thing.

 

[Waira]

No problem Yoz, pics were good enough! Timing is a pain with HPS, can't just turn it on/off like fluoro's and LED,... try for right at lights out, with mild background lighting and use the flash,...
... 0.5EC isn't too bad at all, and it shows in the pH- ..plenty of natural buffering at least!
.... plants are N hogs, and will take it up and store it whether they need it or not! That's why N-tox is so common, IMO.... plant can only handle so much,... BTW, I'd like to use some of your pics for the Diagnostic thread, if that's cool with you! ...great Ca defc. pics on the XL, and the odd ones on the reg. auto are noteworthy as well...

 

[Yozhik]

No problem Yoz, pics were good enough! Timing is a pain with HPS, can't just turn it on/off like fluoro's and LED,... try for right at lights out, with mild background lighting and use the flash,...
... 0.5EC isn't too bad at all, and it shows in the pH- ..plenty of natural buffering at least!
.... plants are N hogs, and will take it up and store it whether they need it or not! That's why N-tox is so common, IMO.... plant can only handle so much,... BTW, I'd like to use some of your pics for the Diagnostic thread, if that's cool with you! ...great Ca defc. pics on the XL, and the odd ones on the reg. auto are noteworthy as well...

re: photos for diagnostic ... GO FOR IT! ... we're all family, so whatever is best for all, is good for me

What can be done about N-tox?
What can be done to prevent the plant from pigging out and hoarding it?
Is it as simple as backing off the Grow nutes earlier?


EDIT:

Just a thought ... if using General Hydroponics Flora nutrient range, would an easy solution to possible N-tox be to adopt the Lucas Formula, given that the theory is based on the premise that the Micro portion gives adequate Nitrogen?

 

[HotBunz]

Yoz,

For what it's worth. I am using the GH Flora line as well with my DWC. I stop using the GROW once flowering is under way. Between the MICRO and the 1-0-0 of the MagiCal I see not need for the GROW.

You are not going to stop the plant from taking up nitrogen. If it's there it is going to take it and will burn itself to the ground if you do not limit the amount in your system.

 

[Yozhik]

Yoz,

For what it's worth. I am using the GH Flora line as well with my DWC. I stop using the GROW once flowering is under way. Between the MICRO and the 1-0-0 of the MagiCal I see not need for the GROW.

You are not going to stop the plant from taking up nitrogen. If it's there it is going to take it and will burn itself to the ground if you do not limit the amount in your system.

Thanks @HotBunz ... today I have done pretty much as you have described, and adopted the Lucas Formula for feeding.
i.e. dropping the GRO and using the MICRO and BLOOM in a 1:2 ratio.

The Advanced Nutrient Cal-Mag+ supplement also has NPK of 4-0-0 ... so its no wonder the poor little ladies were suffering N-tox.
Backing off the GRO is a good start, but I'll need to find a Cal-Mag supplement that doesn't pack a N punch as well - seems counter productive otherwise.

 

[HotBunz]

Yoz,

I use the General Hydroponics MagiCal...it is 1-0-0. Seems there is talk around about one Cal/Mag product that is 0-0-0. not sure what nute line it belongs to.