How to Choose a Fish Tank

When choosing a tank, consider five important factors:

  1. Space in your home

    Ensure the tank you choose has enough space in your home, and determine where your tank will live before you make your purchase. Purchasing a large tank for a small home may create problems if you don’t know where to put it.

    Most large size tanks come with the option of purchasing a stand which is strong and suitable to hold your tank when it is full of water. Ensure you have the room for this as well, as placing your tank on a different piece of furniture may result in damage. You’ll also need to ensure that the flooring beneath your tank is suitable to hold its weight when full.

    Keep your tank away from areas where external sources like windows and heater vents will affect its temperature. Also, try and keep your tank out of direct sunlight as this will promote algae growth.

  2. The amount of fish you’d like to keep

    The more fish you keep, the bigger your tank will need to be. Overcrowding a small tank with any type of fish will result in your fish either outgrowing the tank or unnecessary stress placed on the fish that can easily result in illness and/or death.

  3. The type of fish you’d like to keep

    Most fish purchased are young and not yet fully grown. Ensure your tank has ample room for your fish to grow. Different species grow to different sizes – your local PETstock fish guru will be able to chat with you about this and help determine which breed of fish is most suited to you.

  4. The time you have to maintain your tank.

    The larger your tank, the longer it will take to properly care for so keep this in mind when considering how much time you’ll have to maintain your fish family’s home.

    For example, an aquarium of about 200L+ that is fully stocked with fish might take a couple of hours to maintain every fortnight (approximately). Maintenance frequency depends on a number of factors so this estimate may be more or less.

    Below is a rough guide of tank sizes, fish capacity and maintenance frequency.

    Tank Size

    Fish Capacity

    Maintenance Frequency

    20 Litres 2 fish Every Fortnight
    90 Litres 10 fish Every Fortnight – 3 weeks
    165 Litres 15-20 fish Every Fortnight – 4 weeks
    *Fish numbers are based on a 5cm fish size.
  5. Your budget

    An obvious one but don’t skim over it! The bigger your budget the more equipped your tank can be. There are some varieties of tanks that may be the same size but different in cost. This is mostly due to what the tank includes. The more expensive option will most likely include a built in light and filter whereas the less expensive option may have neither (a filter is essential so will need to be added if your tank does not have this). In general, most new tanks come with a light and filter built in. Your local PETstock team can help find a solution within your budget.

What do I need when purchasing an aquarium?

To make the set up process as easy as possible, you’ll need the following items when purchasing your aquarium:

  • Water conditioner
  • Ammonia, Chlorine and Chloramine eliminator
  • Live Bacteria - API Perfect Start is a great kit to purchase for smaller tank sizes as an all in one set up product. It contains three envelopes of treatment to use on day one, day 14 and day 28 to ensure your tank set up is as easy as possible. Seachem Head Start is the alternative to this for larger tank sizes.
  • Conditioning salts
  • Gravel
  • Filter (if your tank does not come with one)
  • Heater (if you would like to keep tropical fish)
  • Live plants
  • Ornaments and aquarium background (optional)

Purchasing fish on the same day as your tank is NOT advisable. Letting your tank cycle for at least one week before adding fish is essential to allow the tank’s natural biological filter develop. Please see How to set up a Fish Tank: A Step by Step Guide for more info.

Our Recommended Products

API Quick Start Aquarium Water Conditioner

  • Immdediately kick starts the natural aquarium cycle.
  • Contains nitrfying bacteria helping to establish the biological filtration process which consumes ammonia and nitrate.

API Perfect Start

  • Consists of 3 envelopes to use on Day 1 when setting up the aquarium, Day 14, and Day 28 after the aquarium is set up.

Aqua One Gravel

  • Provides aesthetic appeal to your fish tank
  • Substrate for live plants and aqua scaping
  • Aids in biological filtration, providing a substrate or "home" for the beneficial bacterial colonies that help keep your fish healthy.
  • Immitates their natural environment which will reduce stress levels in your fish.

Aqua One Clear View Hang on Aquarium Filter

  • Ideal for garden aquariums or inside tanks where a submersible filter would take up too much space.
  • Provide high levels of filtration through an easy to remove and replace filter cartridge.
  • Removes debris, tannins and harmful chemicals from your aquarium water.

Aqua One Barrel Aquarium Ornament

  • Increases the vibrancy of your aquarium.
  • Great way to conceal unsightly submerged equipment that can ruin the appearance of your aqua scaping.
  • Provides a place for your fish to hide if their tank is in a high traffic area, or if you have more territorial fish in the same tank.


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