Black spots on leaves please help!!!

Hi so I have black spots on 3 of my plants, They are under cob led the vero 29s to be exact, Then I also have the same strain under a hortilux blue bulb and it is getting the same feeding and the plants look perfect, I also switch from hortilux blue to the cob leds during week 3 of veg, Please help if anyone has any idea what is going on, I am feeding at 800 ppms and 5.8-6.3 ph

hmm got any more pics of your issue ,here is a list with pictures of different types of plant or leaf problems,may help you to diagnose your issue,hope this helps

http://www.growweedeasy.com/marijuana-symptoms

Either Phosphorous (P) Deficient or Cal/Mag Deficient, but I'm leaning towards P.

I'd also feed closer to 6.5PH in soil. (6.3 to 6.8PH)

Is the problem more prevalent towards the bottom fan leaves?

I don't think it's the LED lighting. Could it be a different Pheno or is it a cutting? (Maybe a picky Pheno compared to your other plant?)

What nutrients are you feeding?