No need to even tighten any fitting that tight, use Teflon, lots of it, make sure you put it on the right way, there is a proper direction to wrap Teflon, of you can use the Teflon goop and then thread together, but the. You run that dangerous risk of over tightening. Go just until snug. Pipe threads are all built and designs with a slight taper to them like a pyramid, where as normal nuts and bolts are not, so as you tighten a pipe thread up its getting larger and trying to jam more pipe inside the hole, if you over tighten it you can then start to stretch and warp the plastic pipe or fitting you are working on.
Get it part, Teflon about 20 wraps on it and put it back together, nuff said
Sent from my iPad using Tapatalk