If you're connecting a new toilet or installing a shut-off valve on an old toilet, you'll have to connect the water supply line to the toilet tank. The type of tubing you choose will determine how difficult this job is. While HammerZone.com recommends a sturdy section of chrome-plated tubing, it can be difficult to bend. If you want to make the job easier, go with a section of flexible tubing instead.
Shut off water at the main.
Screw the stop valve's nut into place so it is securely connected to the water supply.
Connect the new tubing to the toilet by threading the white plastic nut into place. This will help you see how it lines up with the shut-off valve so you know where to bend it.
Bend the tubing with the help of a tubing bender, unless you have chosen flexible tubing. Align the bent tubing once again with the shut-off valve.
Cut the excess pipe with a pipe cutter so the pipe extends about 1/4-inch into the shut-off valve.
Connect the top to the tank by threading the plastic nut into place. Insert the brass ferrule into the stop valve and tighten the compression nut at the shut-off valve completely, but not excessively, or you could damage the tubing.
Turn on the water at the shut-off valve.