When tea steeps, tannins (the natural compounds that color tea leaves) are released into the boiling water. The heat helps dissolve them, and the brew is clear enough to see through.  Refrigeration can cause tannins to separate out again, turning the tea murky. Generally, higher-quality tea contains more tannins (because it is richer in solids) and is more likely to become cloudy.  

• Hard water can also make your iced tea cloudy. Also the minerals in your water could be causing the cloudiness. Try using bottled or filtered water and let the tea stand at room temperature for an hour after steeping.
   

• Do not use cold water (use room temperature water).
   

• Do not add ice to hot tea, only add the ice cubes to your drinking glass and then pour the tea over the ice cubes.
   

• Do not put it straight into the refrigerator after it's made. Let it cool at room temperature first. THEN put it in the fridge. Cooling too fast makes the tannin settle out, causing cloudy tea.
   

• If the tea turns murky in the refrigerator, add a cup of boiling water to one quart of tea - it should clear up the cloudiness. Remember, it will also dilute the tea, so add less ice.