three children looking at an aquarium
Any transparent vessel capable of holding water, even a Mason jar will make an aquarium from which a great deal of pleasure may be derived. The old way of maintaining aquaria in good condition required a great deal of care and attention. The water had to be changed at least once a day if running water was not available, and altogether they were so much trouble that as a rule owners soon tired of them.
Modern aquaria are totally different. By a proper combination of fish and growing plants we can almost duplicate the conditions of nature and strike a balance so that the water need never be changed except when it becomes foul or to clean the glass.