When i change my res i add nutes at around 850 ppm for veg. This brings the pH to around 6.3 to 6.5. So i add pH down then i measure the ppm and it is up around 2000 to 2100 ppm. The back of the bottle says pH the water around the 5.5-5.8 after the nutes are added. ​Is this normal, or...