Nitrates are the final product of the nitrogen cycle in the pond. Nitrates are produced when the nitrifying bacteria called Nitrosomonas break down the ammonia into nitrites and nitrate soil.

Whilst nitrates are seemingly not as dangerous for your fish in comparison to ammonia and nitrites. The level of nitrates should be kept as low as possible. If the level of nitrates rises, the level of harm this can cause your fish will rise as a consequence, and can potentially cause a serious threat to the life of your fish.

Signs of nitrate exposure:

  • Your fish appear stressed.
  • The fish are not thriving as they should and seem to have difficulty growing.
  • Poor health due to potential internal damage of the organs.
  • Compromised immune system.
  • The fish appear tired and lack energy.
  • Paler in appearance.
  • Loss of appetite.
  • Gasping at the surface of the pond.

Nitrates can cause a build up of algae which can cause additional problems as this can cause a depletion of oxygen with the pond. These additional complications also cause an immense risk to your livestock.

There are a few ways in which you can help to maintain the appropriate level of nitrates available in your pond:

  • Add additional plants as plants use the nitrates during photosynthesis, but please bear in mind that if you overstock your pond with plants this can have an adverse effect on other levels which need to be maintained within the pond.
  • Reduction of waste do not over feed your fish.
  • Do not over stock your pond with fish.
  • Have your pond regularly maintained.
  • Ensure your filter is adequate for your pond.
  • Consider regular water changes with your maintenance.

Nitrite naturally occur in your pond and need to be kept at a reading of ZERO ppm, however a slight deviation to a reading of 0.02ppm is acceptable however not ideal. If you have a reading of anything above zero for your nitrite levels, then please call as this may require immediate attention, as this can be detrimental to the health of your fish and pond life.

Symptoms of nitrite poisoning are remarkably similar to the symptoms of ammonia poisoning.

  • Stress, this could be a lack of appetite, lack of movement, appearing tired and lethargic.
  • Flashing.
  • Jumping.
  • Gasping for air at the surface of the pond.
  • Have a nose down appearance.
  • Sores/irritation appearing around the gills.

Nitrites prohibit the fish from being able to successfully transport oxygen within its bloodstream, this causes your fish to become oxygen deprived and can lead to suffocation from oxygen deprivation.

In addition to this nitrite poisoning can cause “Brown blood disease.” This is due to the nitrites binding the haemoglobin in the blood and preventing the binding of oxygen. The fish’s blood will appear to be brown in colour, due to the lack of oxygenated blood, as opposed to being red. Brown blood disease is dangerous to your fish and can be fatal.

Nitrites are made by Nitrosomonas bacteria also called a nitrifying bacterium, this bacteria is known as a chemoautotroph. This means that they can create their own food and energy from the fixation of carbon dioxide. The energy that they spend for this comes from the oxidation of ammonia and ammonium-based compounds. They break this down into nitrites and soil nitrates.

The other contributing factors which can cause elevated nitrite levels:

  • Inadequate filtration system.
  • Over stocked pond.
  • Over feeding the fish.
  • Poorly maintained pond .
  • Plant fertilisers and other contaminated debris being washed into the pond.

How to prevent future nitrite level fluctuations:

  • Obtain and maintain the ideal filter system for the size of your pond.
  • Undertake regular maintenance.
  • Water changes as and when necessary.
  • Do not over stock with fish.
  • Do not over feed your fish.
  • Introduce a few plants to your pond as this will help to reduce the number of nitrites and increase the amount of oxygen in your pond.

If in doubt call the pond medic today! Tel: 07737 674417