Man 4ml of ec part nutrient is CRAZY, your water is lava! Of course you are getting ph 2.0 , you are adding a ton of ph regulator , I was good with 1ml each, 2of the main phase ( veg or bloom ) if needed. Make sure your ph pen is correcly calibrated and stored ( with a storing solution inside the cap) and only cleaned with a tissue. Also with ph problem you get ec problems with that dosages, and if you see your plant is stunned