No. Do not feed that low. You haven’t grown HPA for a long time, and never really grew “true” HPA because you neglected to add an accumulator or solenoids. This means that your misters were dribbling for a short time before reaching target pressure and after the pump shut off. I’m still learning how to grow HPA and I wish that there wasn’t so much misinformation out there. I feed around 1.6EC to mature plants (of megacrop, or about 1EC elemental base nutrient), and even to my tiny seedlings and established cuts when they get transplanted into a bucket in my HPA system, and grow true (90-100psi) HPA. I’m still a noob, but feeding at nutrient concentrations that low causes all kinds of problems. Richard Stoner of agrihouse (who invented the HPA unit that NASA grew plants in) says that you should feed about 600ppm TDS (1.2EC) elemental nutrients. Which is right in line with what I feed now with the fertilizer I use. If you want an easy nutrient to start with, use greenleaf megacrop. You do not need a bunch of additives.