TPA black tea

I have some TPA black tea flavoring. It seems to be extreay strong. My last batch mixed was 5% flavor 15% sweetener and 80% 50/50blend. I want a southern sweet tea flavor but can't seem to get it. I can buy good sweet tea juice but would really like to mix my own. Have read several posts about the strong Oder and taste of this black tea but haven't found any that have made it taste good. Do I need to dilute it before I mix? If so at what %? Am I useing to much? If so what is a good % to start at? Any info would be greatly appreciated. Thanks Matt