Set your tricools to the low setting, and run TAT on your CPU and see how hot it gets. If it gets too hot, put the fans at medium and repeat.
Find a good balance between temperature and noise, then leave your fans at that speed. You shouldn't need to ever look at the fan speed, it's not a necessity, especially if you have lots of margin. Don't tune to a few degrees close, as CPU coolers gather dust over time and lose a bit of heat transfer efficiency.