You don't need any of those chemicals for a clean tank. My guess is your tank is too small and.or your filter is too small. For tanks over 30 gallons, I suggest getting an external canister filter, such as Fluval 404, Filstar XP3, Eheim 2026 or Eheim 2028 and I hear Magnum 350s are good as well.
I run canisters on most of my tanks and never do a complete water change. About every two weeks, I change half the water. Vacuum the gravel, if I use it in that set-up and maybe scrub some algae away. That's it. The canisters do a great job at keeping the tank clean.
Cheers,
JJ