Fish Tank Water Preparation Step-by-Step

A fish aquarium.
  • 2 hours
  • Intermediate
  • 50
What You'll Need
Tap water
Sodium thiosulfate

Once you have purchased everything you need for your fish aquarium, you may be tempted to just fill it with water, buy some fish, and put them inside. However, you will need to prepare your fish tank water first.

1. Set Up Tank

Rinse off and add any gravel, rocks, and decorations to your tank before adding water. Once you have things set up, fill the tank with tap water.

2. Filter Water

Plug in and turn on the pump in order to filter through the fish tank water. This will help oxygenate the water for your fish.

3. Treat Water

Tap water usually contains chlorine, ammonia, and other chemicals that can be harmful to fish. You can use sodium thiosulfate. Your local pet store will have it and any other products to treat and neutralize these chemicals.

4. Leave Tank

Leaving the pump on, let your tank run for at least 24 hours. Ideally, you should let your tank run itself for a week before adding any fish. This will help create a water cycle before adding your fish. It will also give any treatments that you added a chance to work.

5. Introduce Fish

Once your fish tank water has established a cycle, you can slowly begin adding fish. You should add one or two fish first, and leave them for a week to see how they do. If you add too many fish at once to a new tank, it could upset the balance that was established, and kill all of the fish.