Add the clams and mussels to a bowl and cover with cold water. Add a handful of salt and soak for about 15-20 minutes. This will help all the sand come out and settle to the bottom of the bowl.
Put a large stock pot over a medium flame and heat the oil. Add the garlic and red pepper flakes and cook until the garlic is golden, about 30 seconds.
Add the calamari, the mussels and the clams. Saute` for two minutes. Then add the white wine and cook for 1 minute.
Add the cherry tomatoes, shrimp and scallops to the pot. Stir to combine. Cover and cook until all the clams and mussels are open, about 5-7 minutes. Stir in the parsley.
Taste for seasoning and season with salt and black pepper as desired. Serve with crusty Italian bread for dipping.