I currently own a Ferro Concepts FCPC V5. I just received my zip on Back Panel for my water storage. Dimentions of the Panel is 11.5”x 8”. Says it’s fits a 1.75 liter Bladder. Im having trouble finding a quality Water Bladder that will fit inside the Back Panel. Any suggestions? What is everyone else rocking for the water bladder on they’re FCPC?.