what makes LR
live is the life ON the rock. bacteria, worms, algaes, etc. Exposed to air (or pure FW
I would imagine), many of these organisims will start to die (this is why shipped LR
always suffers from die off) If the LR
were left in the air for an extended period of time all the life on the rock would eventually die and you would have "base rock"
But... juse because what's on it is dead, does not make it useless. Base rock placed in a tank with other LR
can re-establish itself with bacteria and the other life forms.