Hey!
I saw your using bloom nutrients. Thats good because some tips look like phos
Remember that once leaves phosphorous or potassium deficiency..
I'm still leaning strongly on the cal-mah situation, like you said it's gotten worse..
Those yellow leaves are clear sign of magnesium defeciency.
Brown rusty spots are calcium defeciency.
Don't go too hard on nutrients now though, from not giving any to suddendly giving a lot you could cause nute lock.
Also remember it takes 3-4 days for plants to assimilate and show whats going on in the roots..
Keep an eye but be patient.
Good luck and happy growing!