[hoppycalif]

Pipe threads always require either teflon tape on the threads or pipe dope on the threads before screwing the pieces together. Those things lubricate the threads so they tighten better, and they seal whatever small gaps there are between the two sets of threads. Personally I prefer pipe dope, but I use both.

 

[hoppycalif]

They both work fine. I sometimes get two thumbs on one hand, and find it hard to stretch the tape over the threads. And, sometimes little tiny pieces of the tape get inside the pipe, where they can do some harm in some situations. Lastly, the pipe dope always seems like it would be more forgiving of not quite tight enough joints, but I admit I rarely see a leak with either method.

 

[hoppycalif]

The taping looks ok to me. It should go on in the direction so that when you screw the fitting in it doesn't loosen the tape. Getting pieces of teflon in the water isn't a problem, that I know of, but getting it in a CO2 regulator or needle valve can be a big problem.