@rkymtnman how do I use the ec scale, my meter has thatmy point is don't try to hit a random target of 1000ppm, work your way up to it IF the plant can handle it. and you use your meter to do that. you want a slightly dropping ppm every day.
your numbers of 1200ppm would kill my plants in a day. i rarely go above 600ppm during full on flowering.
every strain you grow will be different so learning how to use you ppm meter to see how the plants are eating is a great skill to learn as a beginner.
I use an EC meter to avoid confusion of the 0.5 vs 0.7 scale with ppm. i would guess that the 500 ppm light on yours would be 500 ppm. so start there and see if it drops the next day.