900psi is average for room temperature CO2
400-500psi is average for fridge/kegerator/keezer temperatures.
pressure decreases as temperature decreases.
you don't have a leak. if the cylinder was empty it'd be almost 0psi. as long as there's liquid inside, you get normal pressures.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10