Keeping fish may sound easy, but it can be quite challenging. However, if you meet the various conditions necessary for their survival, keeping them becomes manageable.

However, the challenge lies in understanding the conditions they need for survival and figuring out how to fulfill those conditions to a satisfactory level.

For fish living in water, water quality plays a crucial role in determining their environmental conditions, maintaining their vitality, facilitating cellular activity, and supporting physiological functions, including reproduction.

1. The first and foremost factor is water clarity, which must be crystal clear, summarized in one word: clear. Many subtle surface issues with ornamental fish are not visible, especially in tanks with brown algae and various organic substances covering the walls. This is extremely unfavorable for observation. Additionally, if the water quality turns yellow, dark, or green due to excessive coloration, it may not be considered suitable for a healthy tank.

Tap water, when initially added to the tank, may be clear but not transparent – the second aspect is clarity. If tap water has minimal impurities, it may appear clear when added to the tank. However, after introducing ornamental fish, the water quality might change due to everything in the tank not being matured, including beneficial bacteria.

Consequently, the water quality undergoes some variations, and a matured tank water should not only be clear but also relatively transparent, providing a visual effect from different perspectives.

Assessing the quality of tank water requires considering transparency. It should not only be transparent but also bright – the third aspect is brightness. A good tank of water must have a certain level of brightness, not excessively dark or murky, ensuring a comfortable appearance. Transparency contributes to brightness, and this brightness refers to the inherent luminosity of the water itself.

Clear, transparent, and bright are not necessarily the only criteria for good tank water, but they represent the minimum requirements and visual judgment standards.

2. Water temperature is another critical factor. Different fish species have varying temperature requirements. Deviations from their preferred temperature range can result in reduced vitality, decreased appetite, or even disease and death.

Generally, freshwater fish are roughly categorized as coldwater fish (15-18°C), warmwater fish (23-30°C), and those in between (18-25°C). Most ornamental fish, originating mainly from tropical and subtropical regions, have an optimal temperature range between 18-30°C.

3. Tap water from surface water sources like reservoirs is commonly used for daily activities and as the primary water source for aquariums. While tap water is stable and clean, it may contain added chlorine or chloramines for disinfection by water treatment plants.

While these disinfectants are not acutely toxic to humans in the concentrations found in tap water, many aquatic organisms are sensitive to them. Therefore, when using tap water for fishkeeping, it is crucial to address the chlorine issue.

In summary, keeping fish requires maintaining suitable water conditions, and adjusting parameters such as water quality, temperature, and acidity based on the habits of the fish. Additionally, attention should be given to stocking density to ensure the health and comfort of the fish. If you have any questions or concerns, feel free to consult with professionals.