Corey,
Your picture was of the pressure tank and recovery reservoir for the Hurricane system. Your hurricane system has a double wall heat exchanger that is designed to use regular automotive ethylene glycol coolant. The Hurricane system will usually self bleed any small quantity of air as it runs if you completely fill the pressure tank (black tank with radiator cap) before start-up and have the recovery tank at the "full hot" mark after it reaches operating temperature.
The term "pet friendly" on automotive antifreeze does not mean that it is nontoxic. It just means that a bittering agent has been added to it so that pets will not drink the normally slightly sweet antifreeze if it spills on the ground. If you want nontoxic coolant to use in your Hurricane or Aqua Hot system, you need to use boiler fluid instead of automotive coolant.
Gerald