I make sun-tea all the time. Long before it be came the "in" thing. I never let my tea sit out for hours. I start with 1 gallon cold water, and add 8 Lipton tea bags. Mine is always ready in about an hour after setting in the direct sun.
I remove the bags, and store in my refrigerator. It is always fresh tasting on the third day, if it lasts that long!
Marion