Yellow leaf spot?

[Cannacaps4U2]

Hi all
I am 6 to 8 weeks into flower (depending on when you start counting)
Northern Lights photo period.
Indoor cabinet 48 h x 36 w x 20 deep.
Two plants using a homemade SCROG setup.
Grown in FF Ocean Forest.
Today I noticed these spots just starting on a few top leaves.

I have pretty much decided to watch and wait.
I am still feeding 2 times a week with FF (bb, tb, gb) according to the FF feeding schedule.

Will flush in a week or so for final two weeks.

Any Ideas what this might be?
Kind of looks like calcium deficiency?
Or maybe yellow leaf spot?

 

[BooMtoLate]

Yes looks like calcium deficiency to me

 

[MrSauga]

You have a couple of things going on. N tox causing the leafs tips to curl under and the Ca def as diagnosed above. I'd look at maybe dropping some of the N from the lineup and adding some calmag with a low N content, like 1 or 2%. If you P levels are high you're reducing the availability of Ca uptake as well, so overall you should look at your NPK ratios. Try and balance the lineup to something like 23 ratio of NPK.

 

[Stltoed]

You have a couple of things going on. N tox causing the leafs tips to curl under and the Ca def as diagnosed above. I'd look at maybe dropping some of the N from the lineup and adding some calmag with a low N content, like 1 or 2%. If you P levels are high you're reducing the availability of Ca uptake as well, so overall you should look at your NPK ratios. Try and balance the lineup to something like 23 ratio of NPK.

I agree with Sauga looks like a Nitrogen excess. Flush em with Fulvic acid and start again with little to know Nitrogen. Your calcium probably has Nitrogen in it. Grow More makes a Calcium with no Nitro I believe. Your flowering will basically stop if it is a Nitro issue. A fulvic flush will help regardless. Double check your Ph.

 

[Cannacaps4U2]

Thanks for the help.
I have flushed and will use plain ph water to finish these