500 grams (1.1 lbs) elbow pasta1 kg (2.2 lbs) clams350 grams (12.3 oz) cooked mussels1 onion, finely chopped3 cloves of garlic, finely chopped250 grams (8.8 oz) shrimp meat (80/100 count)250 grams (8.8 oz) crab meat1 tablespoon tomato paste1 small pack of tomato passata with oregano and basil1 tablespoon garlic powderSalt, to tasteOlive oil, as neededWater, as needed