Excellent post Delta, I read the whole thing and learned a great deal. I am using Flora series nutrients and R/O water. Flora has a separate Hardwater micro for their hard water. So I am assuming the regular micro has the cal mag i need. I was interested about two thing though:

Mixing tap water and R/O, this would be a great way to get around the ergonomics of my R/O, as it only produces 5 gallons every 1.5 hours and it wastes a lot of water and time in the process.

But more intriguing was the pH discussion. I heard keep it between 5.5 and 6.5 so when I started my seeds yesterday I used 6.34. I'm now wondering if I should attempt to drop the pH.