Hi all and thanks for reading, I need some help with compression fittings. I installed a water filter for my fridge and a faucet on the sink. I used 1/4" copper tubing and B&K 1/4" compression fittings from Lowe's. The fittings do not have separate nuts and ferrules. They are one assembly. I cannot get these to stop leaking. I cut the copper with a good cutter. I just snugged the nut and anticipated a slight leak. I figured I would slowly tighten them until they stopped. I've been slowly tightening them with bigger wrenches but they never stopped leaking. I wanted to use copper but is polyethylene tubing and quick connect fittings a better option? Please help. Thanks!