TiAMAT - Speedy Chile (first growth)

Amazing week for growth. LST did its thing and helped my girl to grow bushier. Some huge fan leafs seem to be a bit droopy (dont think its because of over/under watering thou. No fertiliser used yet. I got myself a PH and TDS meter, which got me rather concerned. I watered at around 7.4 ph and 420 ppm but the runoff is off the scale!!! Runoff PH was way acidic..around 5.5 ph. second watering was a bit better but still under 6. Runoff ppm was also worrying of around 2000 ppm. Trying to flush but I have definitely chosen a wrong soil to grow in. Note to myself: dont be a cheapskate and buy a proper soil for cannabis grow. At the end of the week I went away for 2 nights so Tiamat will be unattended, hence 2 days without any progress photos.