Memory Management in MacOS is much more sophisticated than “filling up a jug with water”. It tries to use as much RAM as it needs to; but it will use data compression to compress the least important resources. (Hardware compression is still faster than swapping.) Memory pressure is an indication of how much compression is being used.
Wired Memory is stuff that can never be swapped out: VM buffer caches, IO memory, etc.
Let the OS manage the memory, and if a problem manifests itself, then investigate with the OS-bundled utility. There’s no need in using third-party apps so you can keep an eye on it all the time yourself. Having Humans continually check that computers are working properly is pretty much the opposite of why we have computers.