Fish – Aquarium Setup

23 / Jul / 2018

Before Adding Fish

  1. Wash the gravel thoroughly before addition to your aquarium.
  2. Install the heater, filtration, air pump and attach the background.
  3. Fill your aquarium with water, making sure to dechlorinate it with the appropriate solution.
  4. Turn all appliances on and check they are functioning properly. Make sure to keep your filter always running, even without fish in your aquarium.
  5. Dose the water with a bacteria solution such as Stability, Quick Start, or Biocycle to kick start the biological cycle in your aquarium. (Explained further below)
  6. Add any ornaments and fake plants. It is advised to wait until your setup is ready for fish before addition of live plants.
  7. Wait a minimum of 2-3 weeks for the aquarium water to mature before the addition of livestock. (Explained further below)
  8. If after the minimum waiting period, your water contains nitrate, and has no ammonia and nitrite, then you may add fish.

Waiting Period and the Nitrogen Cycle

Setting up a tank that can handle the addition of fish is a slow process and requires patience. It will generally take between two to four weeks before the aquarium can accommodate a full stock of fish. Your aquarium is essentially a small ecosystem.  It must initially go through important processes to enable waste to be turned into nitrates (Nitrogen Cycle) which is less toxic for your fish.  This in turn helps avoid what is known as ‘New Tank Syndrome’. The Nitrogen Cycle can be best explained by the following diagram:

Ammonia and nitrites are very toxic for your fish!  Your objective in setting up an aquarium is to grow Nitrosomonas bacteria and Nitrobacter bacteria within your filtration system that can turn these toxic chemicals into nitrate which is less toxic.  The Pet Super Store offers a free Water Testing Service (please bring 50mL water).  We can use this test to see how the cycle is progressing/what state your water is in so that you can safely add fish or address problems that are occurring.

Adding Fish to your Tank

When your tank is ready to accommodate life, gradually build your fish stocks up over the following 3-4 weeks.  We suggest adding smaller amounts of fish every 7-14 days, and get your water tested prior to the addition of any new fish within the first 4 weeks to ensure the biological filter is established enough to handle the increase of fish.

For the first few weeks while your tank is adapting to new fish, feed minimally, and do 25% water changes once a week.


  1. After the initial month of weekly water changes, using a gravel siphon replace 25% percent of your water at least once every 2 weeks wi th pre-treated water.
  2. Clean your filter sponges in the water that has been taken out of the tank during a water change approximately once a month to every few months depending on the number of fish in the tank/waste being produced. Be gentle when cleaning the sponges as to avoid killing bacteria that is living in your filter.
  3. Check the health of your fish regularly and ensure that your heater is working. It is ideal to always have a thermometer if you have fish that require specific temperatures.

Golden Rules for Fish Keeping

  1. Never overfeed your fish.
    • The most common reason for problems with water condition tend to be due to overfeeding. If you are having to clean your filter more than once a month or having to do water changes more than once every 2 weeks to keep up with nitrates going in, then consider reducing the amount of food going into the tank.
    • Make sure to purchase a good quality food that is suitable for your specific fish. Higher quality foods reduce the amount of waste that is produced.
  2. Never wash your filter under the tap.
    • It is essential that chlorine never gets the chance to enter your tank. If you add water straight to your tank without conditioning it first, the chlorine in that water can go through your filter and kill all your bacteria that was established during the nitrogen cycle.  This means the tank needs to go through the cycling process all over again.  If this ever occurs, please consider giving us a call for advice.
  3. Consider the amount and type of fish you have for your tank.
    • If you are feeding minimally, and maintaining the tank well, but you are still having problems, consider other things such as whether you have too many fish in the size tank you have, or they have outgrown your tank and are producing too much waste for your filter to handle.