Water polishing

I believe diatom filters pull out the nutrients we add. If it's just a temporary thing for pictures I guess that is no big deal. I used a real fine floss material in my canister and change it every other week. You can buy a big bag for like 10 bucks and it will last forever. It may not be as polished as your looking for though. I guess the question is what is your desired result. Short term crystal clear clarity or simply a better looking tank with sustainable results..

 

Diatomaceous earth filters are very good for what you described. Because they remove so much very fine stuff from the water they won't have the life needed for continuous use, but something like a H.O.T. Magnum 250, charged with DE powder should work very well as a clean up filter. It also works to remove green water algae if that misfortune hits you.