That's so odd. It has been quite a few years since I bought a long length of the tubing, but IIRC I got it at Lowe's. Since my darkroom doesn't have running water in the room, I had to rig up something that ran from the print washer to the bathroom sink next door. It's actually quite comical when I'm running it because there's this long tubing draped around the corners of the rooms with a DIY outlet drain perched over the edge of the sink running into a 5 gal plastic pail. Unlike back in my earlier days when I had real darkrooms, I can't leave it running unattended!
Anyway, glad you got it working.