Part 2 - The Basics!

  • 5 min

Before you add fish, you only need to understand 3 core things:

  1. Anti-chlorine
  2. Good bacteria
  3. Filter + Light

Once you get these right, aquarium keeping becomes easy.

1) Anti-Chlorine (Water Conditioner) — “Make tap water safe”

  • What it is

    Tap water has chlorine/chloramine. These can harm fish and also kill the good bacteria your tank needs.

    Anti-chlorine makes tap water safe instantly.

    When to use it

    ✅ Every time you add new tap water, including:

    • First tank setup
    • Every water change
    • Top up water

    Simple rule

    New water in = anti-chlorine in (same time/or first).

2) Beneficial Bacteria — “The good helpers that keep water safe”

What it is 

Beneficial bacteria are good microbes that live mainly in your filter.
They help break down fish waste so your water stays safer.

Think of them like your tank’s clean-up team.

Why beginners need this

In a new tank, these bacteria are not there yet.
That’s why new tanks can have water issues at the start.

How to use bacteria bottle

  • Add it when you set up the tank
  • Add again for the first few weeks
  • Add again after big water changes
  • Follow the dose on the bottle

Important: Good bacteria need a running filter and oxygen to grow well.

3) Filter — “The engine of your aquarium”

What it is

A filter helps in 3 simple ways:

  • Catches dirt (leftover food, waste)
  • Moves water (keeps oxygen levels better)
  • Houses good bacteria (this is the big one)

Beginner tip

If you want an easy tank, don’t switch off your filter.

  • Keep it running 24/7
  • Only off during maintenance (and not for too long)

Common beginner-friendly filters

  • Sponge filter (simple, stable, easy) hyperlink to the webpage, on how to use it
  • Hang-on-back filter (HOB) (easy and clean look) hyperlink to the webpage, on how to use it
  • Internal Filter (easy, plug and play) hyperlink to the webpage, on how to use it

4) Light — “For nice viewing + for plants”

What it is

A good light:

  • Makes your fish look more colourful
  • Makes the tank look clean and lively
  • Helps plants grow (if you have plants)

How long to turn on the light

To avoid algae, don’t overdo it:

  • With plants: 6–8 hours/day
  • Mostly fish / few plants: 4–6 hours/day

Best beginner move: Use a timer (so you don’t forget).

Super Simple Setup Flow (1 minute version)

  1. Add anti-chlorine
  2. Fill tank with tap water
  3. Start filter (and air pump if needed)
  4. Add beneficial bacteria
  5. Turn on light (short hours at first)

If you tell our That Aquarium staff what you’re unsure of, we’ll be sure to help wherever we can!

🐡 Puffed up with knowledge? Give us a like and keep floating along!

👉 Next Up: We’ll go over how to cycle your tank before adding in your fish!

Author: Kelvin Phua

Illustrator(s): Rong Sheng

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