Hi fella!
I haven't measured this time.. But i think it could be around 1,2 to 1,5 max
I use Bio Canna and normally don't look or change the PH or the EC and the plants are perfect.
Watching at your diary with Big Devil XL Auto, I think you can use the same parameters, you are doing a great work there

Hope this helps you and don't forget to share your experience here in the Sweet Seeds subforum!
Sweet smokes!
jaypp