Calcium deficiency?

[GanjaGed]

Week 6 into flower ( from switch )

DWC

Young upper fan leaf

It's the only problem leaf so far.

[JohnC]

Looks like Ca deficiency but could be a PH fluctuation locking out nutrients. I assume you test your water PH often?

Do you use RO or distilled water? If so, you might need to add a Cal/Mag supplement to your watering / nutrients routine,

[GanjaGed]

Yea, I'm thinking the same. The res recently went from trending up to trending down. PH check daily. RO, I do use Cal Mag but have tapered down to the min dose, I'll try upping it a bit and if it continues just do a res change and see where that leaves me.

Just don't want to get to crazy this close to harvest. Keep 'em green and happy, and ride the last few weeks.

Thanks for the reply John. Always good to check with others and make sure one isn't over-looking something or way off base

[GanjaGed]

So I've been thinking about this and where the problem came in.

I think it is a Calcium lock-out caused by PH, not a lack of Calcium. What's funny is I pretty much posted what I think the answer is but didn't realize it, lol.

As I said the Res went from trending up to trending down recently. So now instead of the res hitting up in the 6.2/6.5 range for a while then bringing it back down I'm bringing it back up but I'm staying in the 5.x area.

I'm hoping it really is just that I didn't account for a full PH range in my drift when the res. situation changed.

[Sheesh]

Hey GanjaGed, I'm not an expert but check out the attached ph range chart If you're in hydro, Ca uptakes best at 5 to 5.8 ish. But Mg uptakes best in the high fives, into mid 6 ph. Ca and Mg work together, that is why Ca and Mg are combined in supplements (Cal-Mag). I don't fully understand the Ca to Mg relationship but it sounds like your thought to change res and up the Cal-Mag a bit may help.

[GanjaGed]

Hmm that's a little different from other charts and from Nebula's article. No matter, I did change the res today and upped the calmag great minds. To close to harvest to let her ass-up now.