Is this powdery mildew or normal?

[Frankster]

I think you got a bit to go there, actually. I would try to darken it up a tad, with some N, and K+, not too much, but certainly some. Those outside (purpling) edges are likely strain, or temp dependent, but it's a form of K+ deficiency, IMO. Note how it's all in the top new growth areas. Clearly, the plant needs to green up some.

 

[rockyracoonface]

Considering it is a learning experience for me I am going to experiment with adding some cal mag to my water. My water is slightly soft and when I gave my tomatoes tomatoe fertilizer in the garden this year for the first time we had a bumper crop of tomatoes. I know I know nothing but that is what a dream told to do and it has little downside. My plants have been somewhat yellow from day one but they grew fairly well. Maybe it is something secondary.

 

[rockyracoonface]

Here is a follow up. I am sure I was slow to address the issue. I tried cal mag on two of my plants in my watering rotation and seemed to make them worse or didn’t help any. Now, I have bought some General Hydroponics and it seems to be slowing down my problem. I think I notice some of the damaged leaves getting some green in them. I’m doing a really low dosage because I am a noob.