How many liters should four small goldfish have?

Four small goldfish should have at least 10 gallons (approximately 38 liters) of water.

Here's why:

* Goldfish grow: While small now, they will grow bigger, needing more space.

* Waste production: Goldfish produce a lot of waste, and a larger tank helps to dilute it.

* Water quality: A larger tank is easier to maintain good water quality, which is crucial for their health.

Important Note: This is a minimum guideline. A larger tank is always better! If you can afford it, aim for at least 20 gallons (75 liters) for four small goldfish.