I have a couple of tanks (29 and 35 gal) and it takes me 20 minutes to siphon the water for a 50% weekly water change and to clean the substrate. I use a python water changer which makes w/c faster.
Feeding is done in a minute per day. I clean the filter media about once every two weeks and it takes about 10 minutes for 2 filters. Monthly, I do a full filter clean and that takes about 15 minutes. So overall,, once a tank is established,, maintenance is ez.