Just wondering if it's safe to keep the C02 tank in the fridge with the keg. If so this will make storing my keg a bit simpler. Otherwise I'll probably have to purchase/build a kegorator.
+1 for that comment. cooler temperature means less pressure produced.
leak test your whole setup first. when you know its good, go ahead and chill the co2 tank in the fridge. it'll end up reading 400-500psi instead of 900psi. but you are NOT out of CO2. some gauges are marked to refill at 450psi.
Like malkore said. Double check your set up first for leaks. I found out the hard way that temperature differences can exagerate weak parts and cause substantial leaks.