Roma tomatoes help

I’ve asked for help with these guys before.
These are Roma tomatoes. Same nutrients. Same lights.
They all look different. The small one on the left that’s yellow appearing is not doing well. Not enough oxygen? Maybe pump too small?
The middle one has these brown spots. The one on the right I think is OK, but looks a little pale.

I need advice would be appreciated.
For nutrients, I was using vivosun base a 4–0 – one and base B one – 4–2
Was using an EC meter, but I’m not sure it’s too accurate as it’s different every time I check