Dice potatoes and place potatoes, ½ c water and ½ tsp salt in a microwavable dish. Cover and microwave on high 6-8 minutes or until tender. Remove from microwave and do not drain.
Dice bacon into ½ inch pieces and chop onion. Place bacon in pan and cook until tender. Remove half of bacon and set aside.
Add onion and pressed garlic to remaining bacon in a pan. Cook 2-3 minutes or until onion is tender. Add flour and cook 1 minute, stirring constantly, until flour is evenly distributed. Slowly add clam juice, potatoes with cooking water, remaining 1 cup water, remaining 1 tsp salt and black pepper. Bring to a boil over medium heat. Reduce heat to medium and simmer 3-5 minutes.
As soup simmers, carefully remove dark reddish brown vein down length of tilapia. Cut tilapia into ¾ inch pieces and add to pan. Cook an additional 1-2 minutes or until is opaque throughout.
Meanwhile, snip parsley. Remove soup from heat. Stir in cream and parsley and ladle into bowls. Top each serving with reserved bacon pieces. Serve with hot sauce, if desired.