What are the most common mistakes made by beginners when starting with aquarium big fish tanks?

Beginners often make several common mistakes when starting with aquarium big fish tanks. Here are some of the most frequent ones:
Choosing an inappropriate tank size: Many beginners mistakenly believe that a smaller tank is easier to manage. However, larger tanks provide a more stable environment for fish, with less fluctuation in water parameters and temperature. Bigger tanks also allow for more decoration and variety of fish species.
Overstocking the tank: Placing too many fish in the tank can lead to overcrowding, which in turn can cause oxygen depletion and increased waste production. This can affect water quality, leading to health issues or even death for the fish. It's crucial to research the space requirements of each species and ensure the tank is appropriately stocked.
Overfeeding: Another common mistake is overfeeding fish. Fish do not have a sense of satiety and will continue to eat as long as food is available, leading to obesity and unhealthy water conditions. It's better to feed them small amounts multiple times a day.
Incorrect lighting: Leaving the tank lights on for extended periods can disrupt the fish's natural sleep cycle, causing stress and potential health issues. A regular day-night cycle should be maintained.
Inadequate filtration: A good filtration system is crucial for maintaining water quality. Beginners may underestimate the importance of a powerful and efficient filter, leading to poor water conditions that can harm the fish.
Ignoring water chemistry: Monitoring and maintaining water chemistry, including pH, ammonia, nitrite, and nitrate levels, is essential for fish health. Beginners may overlook this aspect, leading to unhealthy conditions in the tank.
Using inappropriate decorations or substrates: Some beginners may use sharp or toxic materials as tank decorations or substrates, which can harm the fish. It's important to research and use only fish-safe materials.
Not acclimating new fish properly: When introducing new fish to the tank, it's important to acclimate them slowly to the tank's water temperature and conditions. Failure to do so can cause stress and potential health issues for the new fish.
Ignoring tank maintenance: Regular tank maintenance, including water changes and cleaning the filter and tank, is crucial for maintaining a healthy environment for the fish. Neglecting this can lead to poor water quality and fish health issues.