There are a few programs out there.
There's Baqua and similar, chlorine, chlorine with N2 or Frog (silver cart), bromine, bromine with Frog (can't use N2 with bromine), enzymes and proprietary systems from manufacturers such as HS and D1.
The chlorine and bromine routines are the same with and without cartridges except that the silver may help keep your water better. The proprietary systems are basically N2 or Frog systems on steroids ... the D1 vision cart is huge and expensive.
The truth is we all have clean water assuming you pay attention to it and it really comes down to what you're comfortable with.