Maintaining the Ecosystem of a Freshwater Aquarium

When most people think about an aquarium, they think only of the fish in the tank. It is seen as a glass box filled with water, some fish, and maybe a plant or two. However, successful aquarium hobbyists look at things a bit differently.

The people that have the most success with their tanks take into account the whole ecosystem of a freshwater aquarium. They understand that the aquarium is not just water, fish, and plants, but rather the whole thing is one single living entity.

Approaching the set up and maintenance of a freshwater aquarium in this way requires you to treat each component like a piece of the overall puzzle. When it is time to add some fish, stop and think about how that may affect the other fish, the plants, and the water quality. Everything that gets added or taken out of an established aquarium can have a ripple effect that needs to be considered.

A healthy aquatic ecosystem will have the right balance of fish and plants. It will be getting the proper amount of light. The filter will be keeping dirt in check and the nitrogen cycle will be operating smoothly.

The nitrogen cycle is an often overlooked but crucial aspect of a healthy aquarium. The key to the cycle is the beneficial bacteria that live in the gravel substrate of the tank as well as in the filter. These bacteria “eat” the fish waste and leftover food converting ammonia and nitrites into nitrate that feeds the plants. The plants use the nitrate and with proper lighting, photosynthesize, thus releasing oxygen into the water. The fish use the oxygen to breathe and they in turn release carbon dioxide that the plants use in photosynthesis.

Knowing about this cycle and the importance of keeping it in balance can then guide your decisions as to what to add to the tank. It should be obvious that it would be potentially very bad to add too many fish at one time, as it would create too much waste, the bacteria couldn’t metabolize it all, and the ammonia levels in the water could spike. A sudden rise in ammonia levels could kill both the new and the old fish, so it is of utmost importance to do things slowly when it comes to adding fish to the tank.

Every inhabitant in the tank uses one substance to create another that is in turn used by a different tank inhabitant and so on through the cycle. So, in a healthy aquarium ecosystem, all organisms are in balance, the water chemistry is optimal, and the whole aquarium thrives as one.