Surprisingly, small aquariums can be more difficult to care for than larger setups. The more volume a system has, the more buffering you have against fluctuating water parameters. Accidentally overdosing doesn’t affect the larger volume as much. Small tanks, especially nanos, can fluctuate greatly in terms of water conditions. Temperature, salinity/specific gravity, pH, and others can all rise and fall drastically over a very short period of time. This is obviously not good for the livestock, as it causes additional stress.