There are 3 distinct issues mentioned in this thread: Water taste, water hardness and water safety.
Water Safety: This is easy, the water is safe here, you're not going to be hugging the toilet if you drink tap water. That gross pool water taste and smell? That's the taste of cleanliness baby.
Water Taste: Most people don't like the taste of chlorine in the water. The solution is activated charcoal filtering for drinking water. It's fairly effective at gets rid of chlorine and can be directly applied to the drinking water. A minor down side is it that it filters some of the fluoride out of the water with the initial uses of the filter, so don't forget to brush your teeth.
Water Hardness: Water in Buenos Aires is medium hard. Hard water gums up your pipes and and reduces the cleaning ability of soaps and detergents. It also is harder on your skin / clothes / dishes. You can soften water at any point of the system. If I owned my house here I would install a water softener before the tanks and have a separate unsoftened line go to a drinking tap in the kitchen (Soft water is not good for making coffee and isn't as good for drinking). Alas, I rent, so I've just thrown a cheap inline softener before my dishwasher. Supposedly it prolongs the life of the dishwasher, we'll see. It definitely makes for cleaner dishes with less detergent.