Thanks everyone fpr all the good advice!
I dunno how dh(dear husband) did it! He was cussin' too much for me to be in the room, and I was getting too nervous with the thought of my poor fishies being sumpless through the night. But somehow he did get the bulkhead unscrewed(after an hour of wrenching) and since we had bought two extra overflow plumbing kits, we were in luck and had a new bulkhead too replace the one that had gotten jammed. (We bought the extra overflows to get the new durso that Oceanic is making. I cursed for the extra hundred bucks it cost, but don't you know we have used most of the parts from the extra kits.)We were a bit concerned that the old bulkhead might be leakier, after getting jammed crooked and then being wrenched off. 8O We then put an extra rubber washer on the underside of the bulkhead as well as in the tank under the nut where one is spose to go (?). WAhlaaa! We aren't dripping anymore so not only did he fix the leak, but also the little drip we had from the drainhose that had never gotten solved over the last month of cycling. Gosh! I hope we don't get anymore problems. This new 150g tank has been overwhelming this past month as we have been starting it up. It makes my cichlid tanks look easy!
Mom to the Fab 5!