What’s that:

Odors can originate from different sources. Dead tank inhabitants, frozen food, but also infestation with dinoflagellates or algae can influrnce the smell in the aquarium room or the tank itself. If you detecta different smell, you should find out the source of the odor.


Processes of decay or dead animals in the tank cause a high bacterial load. Rotting of organic materials can release toxins into the tank water which can be hazardous to tank inhabitants.

Measures to be taken:

Odorous substances can be removed from the tank water with activated carbon, aluminium-based adsorbers as well as ozone and a well adjusted skimmer. The regular addition of zeolite powders or mixtures and Coral Balance helps to keep the water clean and fresh.

Indicator species:

General discomfort of the corals. In case of sulphide containing anaerob spots in the aquarium, the first organisms suffering are giant clams, and then later stony corals.


The smell of a saltwater aquarium should remind a bit to the ocean. Some aquarium-related problems can be recognized by a different smell. Dead animals, algae problems, overdosing (e.g. ozone, feed) or malfunction of skimmer. A sulphurous odour can indicate anaerob spots in the bottom gravel (sulphide formation, black discoloration).

No smell:

No action required

Variety Organic, bacteria
Benefits none
Guide value Water smell slightly reminds to the ocean
Skill Level green
Source decomposition materials, yellow matters, dead animals, anaerob spots etc.
Available no addition intended
Importance 1-6 4
Detection quality safe
Relation values none
Fluctuation margin none


Make sure that the food you use is fresh. Frozen food with freezer burn or excessive amounts of food strongly pollute the water. Regular partial water changes also help to keep the water clean. It is particularly important to have a sufficient water flow and supply the system with oxygen. Pay attention to low flow areas and siphone off accumulations of detritus and precipitations regularly.