Hey man. They're in just Jiffy Seedling Mix now, correct? If so, they may need a little Nitrogen at almost two weeks. They aren't too light but they are a little.
Not exactly sure about the soils, ph. I have heard that those Rapidtest meters are no good though, I hope yours is working. You said you're checking runoff too and it's still high. Hopefully, Muddy will be around soon to help more. Sorry I couldn't be of more help.