"The water is bad."
Translation:Das Wasser ist schlecht.
No, the word order is wrong: 'Das Wasser ist nicht gut' - but this is not a valid translation of the English sentence.
I'm a teensy bit peeved that getting the form of the counts against you when testing out. As a former teacher of mine said, it's like when people mix up your/you're. It's still a perfectly understandable sentence
böse is more explicitly "evil" while schlecht may merely be "bad". böse can also mean "angry".
wertlos means "worthless".