Yellow Spots on Leaf, any ideas?

So for a while my Kali Mist has had these yellow spots on her leaves. My water is really soft, 38 PPM so for the past few feedings I've been giving some CalMag 0.5ml/L but the problem seems to be getting worse... My other plant has had the exact same treatment and is a week or so behind and has nothing wrong.


Since the Kali's Coco Mix is a lot lighter than the other, really spongy in fact, could it be this causing Yellow spots?


I've been feeding them both at PH 5.8 @ 240 PPM


The brown burns are from Lime, they haven't changed since.


Cheers for the help!

Check out this thread here on RIU or this thread at MJGrowing, mate.
I'm not positive on the cause, but others have had the same issues and it seems common.

Real wet can do that. Bump pH up to 6.5 if not coco.

I'm letting them get quite light before watering, basically water every other day. I might bump the PH from 5.80 to 5.9, as magnesium get's locked out below 5.8 so will see how that goes! Although since it might be quite loose there could be too much water getting to the roots..