Deficiency early flower

[Th3Grow3rNooB]

Hey guys. Mid week 3 flower going into 4th. All was well untill this problem, only on a few fan leaves atm, so not a train wreck. Any ideas however ?

Growing in Cocos 30% Perlite.
EC in is 1.55 to 1.58 - PH in is 5.9 to 6.0
EC out is 1.68 but slowly dropping
PH out is 6.0 slowly rising.

Is this in need of a flush or should i up my feed ?

 

[Blew Hiller]

Def not a train wreck...can't tell if this pic taken under blurple light or if the leaves really are that dark.

I am a soil guy, but I have seen this question and the answer offered is usually calcium deficiency....so let's ask someone who really knows.... @Chris Scorpio

 

[Th3Grow3rNooB]

There under blurple light myes. And the problem is on the top of plant, i also was heading towards calcium, however my Marine CaMg is 8-0-0 and not recommended after first flowers form

 

[Blew Hiller]

Wait for others to comment but I don't see anything to worry about...adding anything might actually make it worse...

 

[Mayne]

might be a PH issue, you need to start at 5.7ish,

 

[Th3Grow3rNooB]

I heard 5.8 for veg, and 6.0 to 6.2 for flower ?

 

[GrizzWald]

I seem to only have one bit advice lol... Almost didn't answer, as ive only just said same thing to another fella, lol... Anyways, as blew said, add cal-mag, 1-0-0...

 

[Th3Grow3rNooB]

Ca MG still needed after first flowers have formed ? i only have this top shelf stuff which runs pretty heavy, ups the EC by 1.0 at full strength, but at half its dynamite, would it be ok to add a bit off that ? half strength would make it 4-0-0

 

[Weaselcracker]

Calmag is generally added all the way through till the flush, especially in coco. But try to find one without so much nitrogen in it.
I keep my ph low- 5.6-5.8 all the way through. It tends to rise in the root zone anyway- at least in my setup, so I aim a bit low and let it sweep upwards to give the plants a good ph range. 6 and higher (for the feed/water) is too high IMO. Runoff will be higher than that though.

 

[Th3Grow3rNooB]

Thanks dude ill start that and thanks everyone for advice

 

[vyserage]

mine did the same, although on the lower leaf's. Rust spots just like that. Started climbing upwards over time. Issue was pH not getting high enough to absorb calcium and magnesium. If you stopped calmag after flower, that is likely your issue so people up above that said get a lower calmag dosage like Calimagic would do the trick, otherwise its a ph issue.