Place shrimp/scallops in a bowl (You may either coarsely chop the shrimp and scallops, or leave them whole, depending on your preference.) Add lemon/Lime, covering shrimp completely. Cover, and refrigerate for 1 1/2 hours(this will allow the seafood to cook in the Juices, or until opaque and slightly firm.
Add tomatoes, onions, cucumber, radishes, and garlic; toss to combine. Gradually add cilantro and jalapenos to desired taste (jalapeno will grow stronger while marinating). Stir in clam juices to desired consistency. Cover, and refrigerate for 1 hour. Serve chilled with tortilla chips.