Fishkeeping is a fun yet challenging activity, and water quality is one of the key factors affecting fish health. Many novice fishkeepers ask: What kind of water is best for fishkeeping? Can tap water be used directly? Is well water, purified water, or mineral water suitable for fishkeeping? Different types of fish have different water quality requirements, so choosing the right water is crucial for the health and growth of your fish.
This article will discuss in detail the characteristics of different water sources, the impact of water quality on fish, how to adjust water quality, and how to maintain a healthy aquarium environment , helping you provide the most suitable aquatic environment for your fish.
1. Water quality requirements for fish farming
Whether freshwater or saltwater fish, they all need suitable water quality conditions to grow healthily. Generally speaking, ideal fish tank water should have the following characteristics:
1.1 Basic Requirements for Water
✅Clean and pollution-free : The water must not contain chemicals harmful to fish, such as heavy metals, pesticides, chlorine, etc.
✅Suitable pH value :
Freshwater fish typically adapt to a pH range of 6.5-7.5 .
Marine fish are adapted to a pH of 8.0-8.5 .
✅Sufficient oxygen content : Dissolved oxygen (DO) should be maintained between 5-7 mg/L to meet the respiratory needs of fish.
✅Moderate hardness : Different fish species have different requirements for water hardness. Generally, freshwater fish are adapted to water with low to medium hardness (GH 4-12).
✅No harmful gases : Harmful substances such as chlorine, ammonia nitrogen (NH₃), and nitrates (NO₃⁻) should be minimized.
2. Advantages and disadvantages of different water sources
Common water sources on the market include tap water, well water, groundwater, mineral water, purified water, and rainwater , each with its own characteristics.
2.1 Tap water – the most commonly used but requires treatment
✅Advantages :
It is easy to obtain and the water quality is relatively stable.
After disinfection, they are usually free of germs and parasites.
❌Disadvantages :
It contains chlorine (Cl₂) or chloramine , which is toxic to fish and needs to be left to stand or dechlorinated before use.
The water may be hard, making it unsuitable for some soft-water fish.
