Every living thing on this earth consumes water, organic & inorganic matter, grows, reproduces, and dies. In this cycle it generates lots of material which is consumed by other life forms in one way of another.

These cycles are nature ways of ensuring that all elements are always available to various life forms.

Aquariums: Our aquariums are miniature life systems in a glass or acrylic tank. These are closed systems and as such we need to ensure that they remain balanced with all elements to sustain life. In large pond or rivers these systems become self sufficient and various life cycles go on. In small ecosystems, it becomes our duty to replicate these life cycles for a healthy aquarium.

Important Cycles in Aquarium

• Fishes, eat, breathe, excrete, reproduce, die like all living creatures.
• They take in oxygen, food, give out ammonia, Carbon dioxide, poop etc.
• A good system should be able to provide these inputs and utilize the outputs for maximum efficiency.

Thus Oxygen-Cycle, Ammonia-Nitrate cycles are important cycle in a fish’s life. Improper completion of these cycles will result in problems of oxygen deficiency, ammonia poisoning which result in fish getting stressed, lowering of immunity, getting diseases.

In both these cycles plants play a very important role.

Oxygen Cycle: Like most of animals fishes need oxygen to breathe and as they live in water they take oxygen dissolved in the water through their gills. Fishes give out CO2(Carbon dioxide) which is taken up by plants. Plants perform a process called photosynthesis in presence of light, they consume CO2 and give out oxygen which is taken up by fishes thus completing the cycle. It is to be noted that this process only occurs in presence of light. During night plants also take oxygen .In fact in good planted tanks there is no need for an aerator, during sunlight one can also seem bubbles of oxygen coming up from plants.

Ammonia Cycle: Fishes excrete ammonia, and this buildup is extremely poisonous for them. Fortunately there are good bacteria which develop in presence of ammonia and convert this ammonia into nitrites. These Nitrites are also harmful and are further converted into Nitrates. Nitrates are not lethal but are dangerous and need to be removed from aquariums. Now in an unplanted tank there is no way of removing them without doing partial changes of water. As stated above during photosynthesis plants take CO2 & Nitrates and use them. Thus they very effectively remove nitrates using them as fertilizers.

Other Benefits of plants

1. In a new tank they work as sources of nitrifying bacteria.
2. They give fishes a very good place to hide when needed.
3. They prevent algae from coming as all nutrients are absorbed by them leaving nothing for algae to feed on.
4. Rotten food, mulm, debris need to be taken out regularly in a non planted tank, but in a planted tank this serves as a source of fertilizer for plants and need not be taken out.

Nothing in life comes for free; planted tanks come with their own specific requirements:

1. Plants need light, some sunlight gives best growth, but light also gives rise to algae which adds one more dimension to aquarium maintenance.
2. Dying plant leafs & stems can prove a problem.
3. Heavily planted tanks might need some aeration at night as in dark plants consume oxygen and fishes might get low O2.
4. In case of fish falling sick many medicines prove problems for plants.

To sum up DO WE ABSOLUTELY NEED PLANTS ? Mother Nature has evolved for billions of years and given us our earth in its present form. Animals & plants have a symbiotic relationship. In our aquarium, plants will eliminate toxic substances from the water. Why do massive water changes when plants cleanup the water for you ? Keep plants in your aquarium & let them do their work while you enjoy your aquarium.