A question, in an established tank (fully cycled and so forth) is all the sand essentially "live sand", or is it still live sand and playsand? I would assume the former
live sand and live rock both are "live" because of the bacteria that live in them. once you mix playsand with live sand, the bacteria from the live sand will infest the playsand, thus making it live. same thing with live rock - if you add some dead dry tufa rock to a tank with live rock, then it the tufa rock will become live