First broadcast on  

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

When a new tropical fish aquarium is set up care has to be taken to ensure that everything works well, and overstocking should be avoided, otherwise a new filter may become overloaded, in which case ammonia and nitrite concentrations can build up, and poisoning may occur

Here are some key points to consider when creating a new aquarium :

  • It takes 21 days for a new tank to become established
  • Two beneficial bacteria are important in aquaria, 
    • Nitrosomonas - convert ammonia to nitrite
    • Nitrobacter - convert nitrites to nitrates
  • These bacteria can be added to the tank to get it going by :
    • Adding some gravel from an established, disease free tank
    • Adding a starter preparation - commercially available
    • Adding a pinch of garden soil containing the bacteria 
  • To avoid cloudy water wash new gravel up to12 times with a hose until the run off water is clean 
  • Disinfect all rocks before introducing them into the tank using Potassium permanganate - in 3mg/litre water for 24 hours or 15 mins in 7.5mg/litre, OR a special aquarium disinfectant  DO NOT use household disinfectants.
  • Add plants, rocks, set up under-gravel filters etc and switch everything on  for 2-3 days before adding any fish. 
  • Before adding fish to the tank check the following :
    • water temperature (about 24 degrees C)
    • pH (should be 7.0) 
    • ammonia concentration
    • nitrite concentration - should be less than 0.5ppm
  • Start a new tank with a few healthy, hardy species of fish, such as:
    • Barbs
    • Catfish
    • Danios
    • Livebearers
    • Loaches
  • When introducing new fish into a tank differences in temperature and pH between the water they are bought in and the water in the tank will determine how long it will take to introduce them. Tear the plastic bag the fish have arrived in and float it on top of the tank water and gradually add tank water into the bag - about every 10 minutes. Take half an hour if the temperature and pH are similar, but take several hours to fill the bag with tank water if the temperature and pH differences are great.



Updated October 2013