I have a RSR450. I converted the ATO reservoir into a refugium with cheato and macro algae. I have a skimmer but no filter stocks. I don’t do water changes. I do an ICP test every 3-6 months and manually dose as necessary. I have a ATO in the basement feeding the tank on the first floor (32G brute as a reservoir). Maintenance is lean the glass as needed, weekly to biweekly empty and clean skimmer cup, and weekly removal of charts. My parameters are not ideal but are very stable and the tank is thriving