The algae that are generally called “brown algae” are diatoms. This type of algae grows only during  a  limited period of time and for the Nature Aquarium, it is usually about two weeks after the aquarium was set  up. After diatoms  are  observed in the aquarium, green algae will grow on the diatoms using them as a base.

In view of this, it is advisable to add living organisms that are beneficial for algae control to the aquarium before diatoms start to grow. Otocinclus, an algae eater, is effective to control diatoms which are highly viscous and stick on the surfaces of driftwood, stone and plant leaves.  The best timing to add the living organisms for algae control to the aquarium should be a little while before algae starts growing, and not after.

Therefore, it is important to closely monitor the changes within the aquarium. The initial stage of the aquarium is too early to add Otocinclus to the aquarium because the water quality is not yet stable and ammonia or nitrite which is toxic to these living organisms may be present in the water at that time. Before adding them to the tank, be sure to check the water quality and observe the living organisms to see if they show unusual behavior due to the aquarium water.

Diatoms grow during the initial stage of the aquarium because the beneficial bacteria within the filter which purify the water are not fully active yet. The growth of diatoms can be suppressed by letting the filter run for about two to three weeks before it is installed in the new aquarium.

To promote the growth of the bacteria for biological filtration, it is crucial to prepare the filter not in a bare tank but in a tank with fishes in which an adequate amount of organic matters are present (in the event only a bare tank is available, it is advised to add liquid fertilizer as if feeding the bacteria in the filter).