Posted by realitychecked on April 05, 2005 at 17:22:02:
In Reply to: Alternative: H Valve and 2nd. 1st stage W/ reg posted by Walt on April 05, 2005 at 17:04:52:
Not a real redundant system in my opinion. You are still relying on a common air supply tank. Redundant regs and tank valve gates yes, but not a true redundant source feeding them. A pony bottle would be a totally redundant source for emergencies but would not be much more safer than a spare air depending on the depth. Twin tanks with an isolator valve (very important) is a totally redundant source for emergencies, but you have to draw the line somewhere.