I just started up my new pump and it is leaking where the threaded pvc pipe goes into the outlet of the pump. The instructions say to NOT use teflon tape but to use pipe joint compound. I did that, and it sat for several days before I started it up - but it leaked quite a bit. Cut the pipe out and tried it with lots of teflon tape, it was better but still leaks. Have never had a problem like this before. Is there some special pipe joint compound I should use, or maybe the threaded pvc connector I have is bad (??) very perplexed.