Anaerobic Spots

A Silent Killer You Could Accidentally Create

- Angel L. Ampil

Ask average fishkeepers what they know about anaerobic spots, and chances are, they will say “What?” and won’t have the slightest idea what it is. After all, the chances are slim that they will be affected by anaerobic spots.

What are they? Anaerobic spots are areas in the aquarium that are deprived of oxygen; thus, they promote the culture of anaerobic bacteria. As we all know, anaerobic bacteria are harmful bacteria that thrive in oxygen-poor water. Once these bacteria are released in your tank, they can do a lot of damage to your water quality, thereby killing your fishes.

How are they made? Nowadays aquariums are usually set up bare and devoid of any substrate or decorations. This allows for good water current to circulate around the tank, thereby ensuring the proper oxygenation of the entire tank. With these bare tanks, it would be almost impossible to create anaerobic spots in the aquarium. With water current freely flowing in the tank, no anaerobic spots in the tank are created.

However, put a flat rock or a tile at the bottom of the tank and this becomes a different ballgame. Between the tile and bottom of the tank is a small crevice that should be filled up by tank water. Despite having a strong current in the tank and the water generally being highly oxygenated, the water in this crevice becomes poorly oxygenated since it is trapped by the tile. Since there isn’t water flowing through the tight space, it is devoid of oxygen.