Doesnt have to be that hard- the little tank i set up only needs fresh water daily (for evaporation) And 10-20L of natural seawater every 2-4 weeks.
oh feed the fish & clean the skimmer. I put aside approx an hour a week for it .
started using Zeovit although that was last year, worst was not taking enough care when setting up a closed loop & coming home to 100 or so litres on the carpet