If you want to use tap water, you need to test your tap water for unwanted additives. Some tap water even carries copper (poison). Get a test kit and test it out for copper and phosphates along with all the regular stuff. If your tap water contains copper, it isn't useable. If it contains phosphates, you'll probably have trouble with algae.
Yes, you will have to use a chlorine/chloramine remover, I suggest something like Amquel Plus. Make sure you get something that removes chlorine and chloramine, as most areas treat their water with chloramine now because it doesn't break down naturally.
Cons of tap water are algae blooms and possible extra additives you don't want, pros are you don't have to buy RO/DI.