I made this beer with 10 IBU and it was great beer. I think it still needs a bit more bitterness to it so I increased the IBUs to 15.96 according to this program.
Also I do not boil for 3 hours. I boil for about 30-45 minutes. After boiling I Open the water faucet to the lowest consistent flow to allow the immersion chiller to cool over night.
I do this because I have a bunch of small kids so I have to break up my brew day into multiple sections which take 2 days. It takes a few hours to get below 200f. For this reason i calculate the ibus to the max bittering capacity.
Let me know if you have any questions.