down the tube(s)
Awry; in a state of deterioration or failure. You got a C average? Boy, your grades have really gone down the tubes this semester. We had big plans for our trip, but the terrible weather made it all go down the tube.
down the tubes
Also, down the tube. Into a state of failure or ruin, as in If he failed the test, his chances went down the tubes. ] Colloquial; 1960s] Also see down the drain.
down the tube (or tubes)
lost or wasted. informal 2001 High Country News I've already lost my alfalfa crop; that's about $20,000 down the tubes.