What causes freshwater aquariums to have an ammonia smell?

Answer by  stschott (47)

It is probably ammonia. Fish waste contains ammonia, which is harmful and can kill your fish. You need to boost your biological filtration so that the nitrogen cycle occurs (look it up). In nature and in properly cycled aquaria, bacteria convert the ammonia into nitrite and then nitrite into nitrate, which is much less harmful to fish.

Answer by  Swizle (28)

Fish urine contains urea and ammonia. A well cycled tank will have a bacteria colony capable of neutralizing the ammonia and keeping your aquarium clean for you. To cycle your tank you need to let the filter run without changing nor cleaning for fish tank for a couple weeks. It will smell bad at first but soon go away.

Answer by  abby39 (213)

The ammonia smell is just what is smells like, ammonia! Fish secrete waste that breaks down into ammonia. To reduce the smell, perform regular water changes.

Answer by  karthick58 (46)

Fish tanks build up beneficial bacteria then convert fish waste (ammonia) into nitrites. Other bacteria develop that convert the nitrites into less harmful nitrates. Your weekly 20% water changes keep the nitrates from reaching toxic levels. If you change too much water, the bacteria go into shock or starve and die off, allowing build up of ammonia while they regrow.

Answer by  mako (289)

The biological filter is not working correctly, or you probably did not cycle your tank before putting fish in it. Perform small daily water changes until problem clears.

Answer by  bbbalooba (52)

The foul almost breathtaking smell of amonia that freshwater aquariums breed off is due to the fish urination which creates the ammonia smell.

Answer by  sparky35 (196)

Excess ammonia causes freshwater aquariums to have an ammonia smell. Your tank should not smell like ammonia at all and this is an indication of larger problems.

Answer by  TMyers (1084)

If it is a new aquarium with all new materials, the chemical levels may be off in the tank. If it is not, everything may just need to be changed.

Answer by  Teresa18 (304)

You may have to many fish in your tank. Check to see if your filters are working and clean. Change as needed.