What is a Balanced Aquarium?
May 6, 2009 by admin
Filed under Keeping Tropical Fish
Originally the concept of a balanced aquarium was that the standing aquarium is a self-contained microcosm - a little world. The theory ran that as the plants manufactured food through the process of photosynthesis; they utilized carbon dioxide and gave off oxygen. Fishes, on the other hand, gave off carbon dioxide and utilized oxygen. Fishes’ waste, according to the theory, fertilized the plants, while excess plant growth provided food for the fishes. One thing thus balanced another, and no outside care was required.
Unfortunately this theory simply does not hold up in practice. While plants do give off oxygen in excess of what they use for respiration, they do so only in the presence of bright light. When the aquarium is dark, they use up oxygen just as do the fishes. Water cannot store more oxygen than the amount required to keep it in equilibrium with the air above it. Excess oxygen passes off readily. The same does not hold true of carbon dioxide. It tends to stratify, forming layers along the bottom. (Circulation prevents this stratification.) Having a maximum air surface in proportion to the depth thus goes a long way toward keeping the aquarium properly “balanced.”
The waste matter produced by the fish is far in excess of the amount required by the plants. Moreover, most of our aquarium fishes are carnivorous, eating animal, not vegetable, matter. Even the more herbivorous species require some animal food.
So the idea of a “balanced aquarium” is a fallacy in its original concept. An “aquarium in balance” is, however, what can be achieved.
The factors that modify an aquarium more or less balance each other includes the proper amount of light (too much over stimulates algae, too little does not permit plant growth); the proper amount of food (too little stunts the fishes, too much pollutes the aquarium); the proper number of fishes; the correct size of aquarium, and the proper temperature, etc. All of these things must be in proper “balance” with respect to themselves and the others if the aquarium is to flourish.
