Can you have a fighting fish small goldfish and 4 zebra in 3L tank together?

Here are the reasons why:

1. Incompatible Species: Fighting fish (Betta splendens), small goldfish, and zebras (Danio rerio) have different care requirements and temperaments. Fighting fish are territorial and aggressive towards other fish, especially those with long fins or bright colours. Small goldfish are active and playful, and require a lot of swimming space. Zebras are peaceful schooling fish that need to live in groups of at least six to thrive. Mixing these three species in a small tank will likely result in aggression, stress, and even fatalities.

2. Overcrowding: A 3L tank is far too small for the number of fish you want to keep. The general rule of thumb for stocking a freshwater aquarium is to allow 1 gallon of water per inch of fish. A fighting fish alone needs a minimum of 5 gallons, small goldfish need at least 20 gallons, and a group of six zebras need at least 10 gallons. Cramming all these fish into a 3L tank will cause severe overcrowding, leading to poor water quality, increased stress, and susceptibility to diseases.

3. Insufficient Filtration: A small 3L tank does not have enough space for a proper filtration system. A good filtration system is crucial for maintaining water quality and removing harmful pollutants. Without adequate filtration, the water will quickly become toxic, causing health issues and even death for the fish.

4. Lack of Oxygen: A small tank has a limited surface area for air-water exchange, which means that the water will not be able to hold suficiente oxygen for the fish. Fighting fish, goldfish, and zebras all require well-oxygenated water to breathe. The low oxygen niveles in a small tank will cause the fish to gasp for air at the surface, leading to discomfort and eventually death.

In conclusion, keeping a fighting fish, small goldfish, and four zebras in a 3L tank together is not advisable. This combination of species and the small tank size will create an unhealthy and stressful environment for the fish, leading to aggression, overcrowding, poor water quality, and insufficient oxygen.