Many of us are fascinated by the breath-taking diversity of life under the sea, which is why owning an aquarium can be an incredibly rewarding and enjoyable hobby, but it’s not as easy as you might expect. It takes research, patience, commitment and a strong sense of responsibility for the welfare of the creatures under your care. While fish, invertebrates and corals do not display emotions as humans do, they can still become stressed in unfavorable conditions and environments. If fish become too stressed, it can impact their immune systems and make them more susceptible to disease and infections. Keeping your aquatic creatures in the optimal environment will ensure their well-being and your enjoyment of your aquarium.

The First Step

Research, research, research

Aquariums are miniature ecosystems that need to be maintained within certain parameters to ensure all inhabitants are happy, healthy and thriving. Getting this delicate balance right, can be tricky but is, ultimately, the key to being a successful and responsible aquarist.

Living underwater, as you can probably imagine, is very different to living on land, and there are a couple of key biological differences between aquatic and common terrestrial pets, such as dogs or cats, that you need to be aware of before you take on the responsibility of looking after these amazing creatures.

Key Things To Remember About Owning An Aquarium

Key differences between mammals (humans, cats and dogs) and fish/invertebrates to keep in mind when maintaining an aquarium:

Aquarium creatures live in water

This sounds pretty obvious, but it’s really important to ensure that you maintain the aquarium water at a high quality to ensure the well-being of your aquatic friends

-The ocean generally changes slowly

Ocean creatures are sensitive to change. Any changes to your aquarium should be done carefully and slowly so that you allow the fish to become accustomed to the changes to avoid stressing them.

-Fish and invertebrates cannot regulate their body temperature

Fish and other invertebrates are ectotherms, which means that they can’t regulate their own body temperatures. If they get cold, they can’t put on a jacket like you and me. If they get too hot, they also can’t sweat like you and me would on a hot day. Therefore, as a responsible aquarium owner you need to make sure that your tanks are kept and maintained at the correct temperature for your specific species. Typically, aquariums contain fish from tropical waters as these are often more colorful than temperate species which means you may need to warm the tanks. Conversely, if your aquarium has cold-water species you may need to chill the water.

-Fish release waste products in the form of ammonia.

At high concentrations, ammonia is toxic and that is one of the reasons aquarium water needs to be filtered. Ammonia is released as a result of protein metabolism and is released into the surrounding environment. Try to avoid overfeeding your fish, as it can lead to a build-up of ammonia that can overwhelm your filtering system. Also, avoid overstocking your tanks as this can also lead to harmful ammonia spikes.

-Any new additions to an established tank need to be quarantined

Before they are introduced, ensure the health of new arrivals and prevent any diseases from entering the environment.Quarantining new additions can also give them time to become acclimated to new the new environment, especially if conditions are slightly different to where they have been housed previousl

-Many saltwater aquarium species are not captive bred but harvested from wild populations.

As a responsible aquarist it is up to you to research the origin of the fish you want to put into your tank and the practices used for their collection and ensure that it is ethical and sustainable


Part of your research should include looking up the care requirements of each species you plan on putting in your tank. Basic considerations are:

  • Compatibility
    • Do all the creatures in your tank require similar environmental conditions, such as temperature, salinity, lighting etc?
  • Many fish are territorial and may therefore be quite aggressive. Aggressive fish may terrorize other inhabitants in the tank and compromise their durability
  • Some fish are schooling fish and therefore are uncomfortable by themselves and need to be around other individuals of their species
  • If you plan on having coral reefs, it is important to check that all the fish you want to put in your tank are coral safe
  • Some species are better off avoiding for beginners
  • Average life span
    • How long do you need to commit to looking after your fish?
  • Adult size
    • It might be cute and sweet now, but fish can grow to be larger than you might expect – make sure that you meet the minimum tank size requirements
  • Feeding 
    • Make sure that you are meeting the nutritional requirement of all the creatures in the tank. Also, make sure you know what your fish need to eat, how much and how they feed

Another component of preparation is one that we usually don’t want to consider or may not even have thought of in all the excitement of setting up an aquarium, but it is important to plan for the proper care and disposal of fish/invertebrates that you are no longer able to keep or have died. You should NEVER release any aquarium creatures into the wild, especially exotic species as it can have detrimental ecological impacts on native species.

The final step in aquarium ownership is monitoring your aquarium and maintaining a healthy system. The easiest way to do this is to establish a routine. This will help you stay on top of any maintenance, cleaning and feeding that your tank requires and will also reduce stress in your inhabitants if they know what to expect.

In summary, the most important thing to remember as an aquarium owner is that the inhabitants of your tanks are living, breathing, delicate organisms that deserve your care and respect. It is your responsibility to make sure that you can meet the care requirements of each individual and are willing to commit to look after them for the duration of their life span.