cal reactor or alk reactor or 2 part?

ok i need some questions answered ive been thinking long and hard about what to do to keep cal/alk level,ive thought about reactors but they seem so complicated,do you have to get both reactors or what? or am i looking at a 2 part system with possible dosing pumps that would be easier then the reactors,opinions anyone?
If that's it, you shouldn't have to dose or have a reactor for anything. I wouldn't consider dosing anything unless your levels can't stay stable for a couple days at a time between water changes.