Leaf Spotting, Dont Know What To Do Next

[Tomcat]

So I have started getting this rust colored spotting on my leaves 5 1/2 weeks into flower. Nirvana feminized ww in dwc using advanced nutrients con. Bloom, b52, big bud, cal mag, bud candy and hydroguard. Ph to 5.6 and rises to 6.2 over 24hrs for the first few days after rez change and then settles at 5.9.

 

[Stoney M]

 

[Stoney M]

Not sure if that helps bud

 

[Stoney M]

Not sure if that helps bud

Potassium deficiency maybe in the late stages

 

[Seamaiden]

It could be, but it looks a lot more like a -Ca to my eyes.

Yeah, it's on the uppers. -K occurs mid-plant. -Ca is uppers, because Ca is immobile.

It's kind of late to start worrying about Ca now, but you're going to have to. You don't mention media so I can't comment on pH.

 

[Tomcat]

It could be, but it looks a lot more like a -Ca to my eyes.

Yeah, it's on the uppers. -K occurs mid-plant. -Ca is uppers, because Ca is immobile.

It's kind of late to start worrying about Ca now, but you're going to have to. You don't mention media so I can't comment on pH.

Rockwool in lava rocks.

 

[Seamaiden]

So a kind of hydro hybrid? I use lava rocks in my aquaponic system, and it tends to stabilize at a pH of 6.4. Of course, it's outside under the sun. I have seen signs of -Ca in it, so I dose with a product called CaFeMg from Sensational Solutions. However, being Ca, and being immobile, it's one of those things that needs addressing from the start.

My suggestion is to try to keep pH shifted towards hydro numbers, and use a Ca-only product (not cal-mag!) as both a root drench and foliar application. You're getting close to end of flower, I would also suggest stopping any additional Ca about two weeks prior to planned harvest.

Despite the -Ca, she looks good otherwise. :)