1 of 3 plants has problems

Biggest plant looks like it has root rot AGAIN there's 3 plants in a rdwc and the other 2 plants roots don't seem bad
Here's pics of the sick plant

These are the other 2 that don't seem as bad. Why is it that the rot is so bad on only one plant? I am running ewc tea.

Plants are 4 days into flower should I switch back to veg untill there healthy again??