Honestly that depends on the brand of nutrients you use.Certainly a prime suspect.... assuming other vitals are in range...what actually IS your EC? above 2.0 and I'd say (in flower) you are getting pretty hot, above 2.5 I would say is way too hot.
do the roots look ok?
You dont need feed as strong as the lable on the nutes suggests with DWC, as with other types of hydro