Help please. Why do my leaves look like this?

[silusbotwin]

Details of the grow are in my sig. Had this same problem when they were younger and I chocked it up as ph problems. Any idea why they have these rust looking spots in between the veins?

inb4 overwatering. It can't be overwatering. I let them dry plenty between waterings.

 

[silusbotwin]

These pictures do no justice. I'm going to take a better photo. brb.

EDIT: Added a photo under better lighting.

 

[bkbbudz]

I am thinking Manganese deficiency from the looks of it. Having never dealt with it I do not know what to suggest. Sorry I could not be more help. Good Luck!

 

[silusbotwin]

I am thinking Manganese deficiency from the looks of it. Having never dealt with it I do not know what to suggest. Sorry I could not be more help. Good Luck!

I'll be adding some CalMag+ to my next feed to see if it helps. Thanks for the advice! Anybody else have any input?

 

[neved]

Thats Mag def . Good used ( cal/ mag)

 

[silusbotwin]

Fed them with a 1/2 strength calmag+ along with the usual Fox Farms feed. Could I have went stronger than 50% strength with the calmag+?

Thanks alot for the help guys! After researching into what mag def looks like, I think you guys hit the nail on the head! What would I do without RIU?

 

[neved]

No ...Dont use more cal/mag .... U just have wait 3-4 days that your plants looks well ....
NOT USE MUCH cal/mag It will make your plants more prblms

 

[silusbotwin]

No ...Dont use more cal/mag .... U just have wait 3-4 days that your plants looks well ....
NOT USE MUCH cal/mag It will make your plants more prblms

I already did a half strength dose of CalMag and they seem to be doing great. It seems as though Calmag is exactly what they needed.

Do you have a moment to explain why it's a bad idea to add CalMag? This FFOF is good stuff but I've read that it always needs calmag added. I'd appreciate if you could explain why you think it's a bad idea. Thanks in advance.