Welcome to the 55G club...
.... Like Melosu said all you need for filtration is good water flow like 2 Koralia a #2 and a #3 for water flow and a good HOB
Skimmer no HOB
Filter is needed. and RO
unit is a very good investment if you want to keep your algae levels down... Remove Phosphates, Nitrates and all the crap you don't want in the water... If you look at BRS
they have good RO
units. When I started just like you I had all the same question so keep asking away.... No dumb question is a bad question here... Also welcome to AA...
You can also look at my Thread
when I started I am still updating it till this day....