Mg lockout? Whats going on?

So my plants started to look really sick lately. I don't think they are overwatered because I only water when the soil is dry.
I grow in Plagron Light Mix soil and started feeding recently with GHE three part.
It looks way more yellow then in these pics.
I use 50/50 RO/Tapwater so i get an EC of 300 and use GHE to get it to 1.2. How often should I feed? Are they defficient because I got lockout from too much nutrients?

Push

Is this plant in flower?

JoeBlow5823 said:

Is this plant in flower?

Click to expand...

No

No one?

Every one of your pics looks like a different plant. Can you get a couple whole plant pics in reg light?

I started giving them a good feeding with 1.2EC. They got a little bit of color back but the problem isnt fixed yet.
I think I have to give them additional Cal/mag because of the RO water. My tap water is high in cal but low in mag so maybe the low magnesium percentage in my tap water is caused by the amount of calcium? I heard of soil growers that got these kinds of problems using too much RO.