Why so much water?
First, all pasta needs room to boil. Second, pasta releases starch into the water as it cooks. If there is not enough water in the pot it can become very starchy and the pasta will turn gummy and stick together.
Follow these steps to awesome pasta:
When cooking pasta always use a large pot and fill with water until about 3 inches from the top. Salt generously - at least 1 tablespoon - cover and set heat to high. I do this first when starting to prep my meal so I don't have to wait around at the end for the water to boil and the pasta to cook. If the water starts to boil too soon and you aren't ready to throw in the pasta, just turn the heat down to a simmer and keep it covered - it will quickly come back to a boil later on. Also make sure that the sink is clean, or at least one side of it is. When the pasta is ready you’ll want to be able to put a colander in there so you can drain out the hot water.
While the water is heating up you should start prepping the other ingredients.
When water for the pasta is boiling and whatever sauce you are making is more or less about 10 minutes away from being ready, A\add the pasta. I always like my pasta al dente so I boil it at least 2 minutes less than the recommended cooking time on the box.
I recommend reserving a little bit of the pasta water for the sauce at the end. [Most sauces can benefit from a little pasta water, it’s salty and starchy and can thicken up a thin sauce, thin out a thick sauce, or make a small amount of sauce go further.] You can do this by taking a measuring cup – or any cup with a handle – and dipping it into the water carefully, until a about a 1/3 cup collects. You may what to use a potholder to protect your hand from the steam of the boiling water.
You can test the pasta by carefully spooning out a noodle [make sure to blow on it!] and biting into it. It should have just a slight bite to it, and a small whitish dot in the center, that’s the part of the pasta that isn’t cooked yet. If it is ready, take the pot - be sure to use potholders since the water will let off a lot of hot steam - and slowly pour the contents into the colander in the sink. Drizzle about 1 tablespoon olive oil over the pasta and mix it around so it doesn’t become stuck together. The cooked pasta can sit like this until it is ready to be incorporated into a hot sauce or mixed into a cold one [like pesto].