Different properties and detections in your water may alter the aesthetics for better or worse. Some minerals, for example, may give your water a pleasant taste. That said, many of the most dangerous contaminants have no taste, smell or color.

At relatively low concentrations, iron may give water an unpleasant, metallic taste and may cause a yellow or reddish-brown color in water and stains on water fixtures and clothing.
Elevated sodium concentrations can impart a salty taste to drinking water. The taste threshold depends on the associated anion and the temperature of the water.
Magnesium, in combination with calcium in hard water, prevents soap from lathering and leads to unsightly soap scum rings, water spots, white film, and scaling on fixtures and dishes. In laundry, hard water can reduce the lifespan of washable fabrics and causes yellowing, graying, and loss of brightness. Hard water can dry out skin and hair. High levels of hardness may lead to bitter tasting water.

High total dissolved solids indicates excessive levels of various ions in a water sample, which can impart a salty taste and color to water. Very low total dissolved solids can make water taste flat.