I am connecting my fridge to the water line as well. However, my fridge doesn't have a connection on it, just the plastic 1/4" tubing. I tried connecting it to the copper water line using the compression joint as you've answered in other questions, but the brass compression part will NOT lock onto the plastic, and thus I have leaks. What type of fitting do i need on the plastic end? Also, if I am connecting two 1/4" plastic lines, what fittings would I buy for that?