Joe,
There's no rent involved. It's free for all SEASL members. There is a deposit to ensure it is returned but as soon as the meter is returned so is the deposit.
N2O Junkie,
You pretty much have to be a SEASL member to utilize resources like the Book Library, PAR Meter, Spectrometer, yada, yada, yada. I'm not saying these will never be opened to non-members, I'm just stating what the current status is.