Making iced tea from tea granules

I assume that the granules don't come with ratios in the instructions. I don't use granules but the way I would approach this would be to measure a certain amount of liquid and add granules to make a single serving of the desired strength ( again a measured amount). Add a bit at a time and write down the extra you add until you reach the desired consistency ( make sure it is dissolved well before you add more and only taste a teaspoon at a time in order to keep the liquid relatively close to initial amount). When you get to where you want to be, divide two gallons by the liquid that you have in the glass and multiply the amount of tea granules that you used by that number. Make sure you account for the added ice cubes which will dillute it a bit more when served. Hope this helps some.