I run a 16 gallon Sera biotop Nano Cube 60 which is listed as 60 liters/16 gallons. I do not have a skimmer.
The tank has been operating since October 2013. Water changes seem to be the key maintenance item. I had it in my office for over a year and would set up an autofeeder on long weekends modified to output a small quantity of Hatchery Diet pellets which is also the main food. This is my first tank and I am happy with the compromises as it has kept me within a reasonable budget of cost and maintenance time.
I have two ocellaris clowns, a red high ray banded goby, pistol shrimp, barnacle blenny, yellow coral banded shrimp and cinnamon shrimp and other assorted inverts. These fish have been with me for over a year.
In my back chambers I simply have some rock and the heater. I supplement at times with filter beds of charcoal and nitrate or phosphate reducers.
The hood seems to reduce evaporation. Whenever I use the feeder which requires propping up the hood, evaporation increases substantially. I have an ATO if that stands for "Administer Topping Off" by hand.
Ironically since I brought it home I have had more difficulty maintaining a constant maintenance with some increase in algae growth. Montipora coral have thrived as well as my Duncan. My leathers have not changed much. My mushroom coral recently replicated after being fairly dormant for a year. So my conclusion is there is a lot you can do with a small tank and modest equipment if you stay constant. Stay observant and you may also learn.
