I am not very diplomatic either but here I go.I get the part about saving for grad school but could you use a little of your savings for a plumber. After all, you are saving on room and board and utilities etc. by living with your parents? And although it may be a health code violation, do you really want to call the health dept. on your parents? If you do, none of you will be living in the house until a plumber fixes the problem.

I really believe I know how you feel. I was 22 once, and I was sure I was the only intelligent person in the house. But if you really can't stand it, you will have to move out and perhaps give up on grad school for now.