also the type of bioload. Corals take alot more work--you have to feed them, move them away from others, replace them according to currents and light needs, glue them back on the rocks when the jumbos knock them over etc etc.
Good point...but corals do not really add to your bioload. Maintaining good water parameters for corals is a priority. However, if no fish reside in the tank, it is certainly a lot easier. Most corals rely on good quality light for energy. Supplementing feedings is light at best. Some nutrients are taken from the water collum but most from the proper lighting. In the properly maintained tank, corals will need to be fragged in time, this does take time. A low maintenance SW
tank is a bit of an oxy-moron, but with the right amount of biological filtration, good skimming, appropriate water movement and light bioload, the work can be kept to a minimum.