Help please. ph problem?

[Ilovevans]

Im thinking i have a ph problem?

5th week of veg

nute line up fox farm trio(grow, tiger, big),cal mag plus, super thrive, RO water

medium canna coco/sunshine number 4 mix


i flushed two weeks ago
humidity, temps are fine

i water every two days. third water is with nutes. cal mag everytime and superthrive.

thanks