Just ordered the Tygon 1/2" ID tubing. Now I need to order some 90 degree elbows for routing the tubing within my case. However, I was wondering if I should get the elbows that have 1/2" OD or 5/8" OD. It doesn't seem like the tygon tubing could stretch to fit the 5/8" elbow and that I should go with the 1/2" elbow and use some good clamps for a nice seal. Any advice from some water cooling gurus would be greatly appreciated as this is my first attempt at such a system.