Acid T800 :
Would it be a good idea to use plumbers tape in my water cooling build? I reference a lot of videos and never seen it once.
The only reason you would need plumbers tape is if you bought local hardware store fittings instead of the G1/4 standard O-ring sealed water cooling fittings of today, as those fittings seal with the provided O-ring as already mentioned above.
Just in case you had discovered that the standard G1/4 threading is exactly the same as 1/4 NPT air tool fittings, and if you bought those fittings instead, they do require using teflon tape to seal.
Tip using teflon tape:
You never ever run the tape to the end of the threads always start the tape one full thread back from the end of the fitting, because the threads will cut off the very end of the tape past the end of the fitting, and it will get trapped somewhere inside your system, more than likely inside your water block.
To be perfectly clear: Teflon tape is only used for hardware available 1/4 NPT fittings, never use teflon tape on today's standard G1/4 O-ring water cooling fittings.