Which size is advisable for a beginner's tank?
the general rule is: the bigger, the better.
Most aquarists start with a 60 cm or 60 liter tank, which is fine for many small fish and shrimps, but is actually too small for several rather common fish species. Aquariums above approximately 100 liters allow keeping more and/or bigger fish.
Good aquarium care is possible also in small aquariums, but a bigger tank is more likely to "tolerate" smaller maintenance mistakes.
Dr. Bodo Schnell