Ok. I'm going through this step by step of how I make a feeding solution, with pics of each step.
I'm using botanicare power flower for this stage. Whaaaat?! But it's a flower fert! Yup it sure is, but there's no better way to scorch seedlings than to give them a big blast of nitrogen in their first meal. The roots and immune defenses need phosphorous and potassium right now, and this is a low nitrogen urea free fertilizer. Urea is the stuff in superthrive and I've seen countless rookies kill their young plants with it. Its VERY available. Be warned.
I'm mixing it at a quarter strength, pH adjusting it to 6.8, and watering to runoff for the first time.
Step 1, checking my tap water. It's holding at 100ppm so I'm not adding minerals. It's fine. And I checked my meter first. It could use a calibration but it's less than 10% off and takes a wonky cal solution that I haven't made yet so screw it. My truncheons are reading even worse. Ugh.
Step 2, adding my 2ml/L. Party trick: write down the dilutions in whatever units you're going to use right on the bottle. Saves a trip to the calculator. Yay, metric.
Step 3, check the pH. Oops it's low, let's bring it up. That's better.
Step 4, water, check fans, distance to light, put your hand at the plants' level for a heat check, take a bedtime puff, and tuck them in for the night.