(HELP NOW)Handling ph in large amounts of water w/ high ppm

man i just made 14 gallons of nuted water at one time....does it always look like this? I had to use 20 tablespoons of ph up(trying to get 6.9-7.0 ph level to balance ph in soil which is a lil low) after giving them a full flowering dose...around 1300-1400ppm i think....the water is like blue almost though...I started watering the first plant...and u can see the shit on the soil...is this normal?...shit makes me nervous...i watered one plant with it and the soil on top is now discolored ...should I be worried?

also im using a ph pen and i calibrated before and during the ph testing.