How to keep cold-water and tropical fish? 8 years of fishkeeping experience and advice for beginners

Although I haven't made any big gains, I have accumulated some small experience. Let me share it with everyone here, for beginners to refer to and for experts to advise on.

Keeping fish is nothing more than water and fish. Water keeps fish, and fish also keep water. Fish without water are dead fish, and water without fish is dead water. So let's talk about water and fish first.

Water: Everyone who keeps fish knows that when keeping fish, you must first cultivate the water. Water is the fish's living environment, but not just any water can be used to keep fish. Some beginners who have just started keeping fish often fall into this misconception when it comes to water: they think that as long as the water looks clear to the naked eye, it can be used to keep fish. Actually, that is wrong. This living environment for fish is very special and complex. Water temperature, the pH of the water, the hardness of the water, the content of minerals in the water, the content of trace elements, beneficial bacterial flora, and so on. These all play a crucial role in the growth and survival of fish. So only by fully understanding water can you keep fish well.

Fish: Because most of the fish we keep now are varieties that have gone through long-term directed breeding, improvement and reproduction by people, and because the varieties are different, the regions where they were bred are different, and the water quality is different, this also determines the different water requirements of fish. You cannot keep all fish with the same water and the same methods; that way you won't produce good fish.

Below I will roughly summarize some personal small experiences from several aspects.

1. Fish tank

When choosing a fish tank, first choose according to the size of the space at home, the color of the furniture and the style of the decor. If the choice is inappropriate, it will look out of harmony with the home environment and reduce the ornamental effect. Second, choose according to the requirements of the fish being kept regarding the size and depth of the tank. Large fish that like to move around should have a relatively larger tank, while small fish that like quiet should have the opposite. Of course, planted tanks for fish are a different matter.

2. Filtration and circulation system

There are many types of filtration now. Common ones include internal filters, top filters, side filters, back filters, bottom filters, hang-on filters, and the plant filtration that some fishkeepers have mentioned. But no matter what kind of filtration it is, apart from looking good, the most important purpose is to maintain good water quality, so that the water can contain abundant oxygen, minerals, various trace elements and beneficial bacterial flora, maintain the pH balance and hardness of the water, and break down other harmful substances for the fish. So you should choose a suitable filtration and circulation system according to your own tank and fish. You must truly achieve the purpose of filtration and circulation. In addition, filter materials should also be chosen according to different fish varieties. Generally, the filtration system we use for keeping tropical fish usually consists of physical filtration (filter cotton), biological filtration (bio-cotton, ceramic rings, etc.) and chemical filtration (activated carbon, maifan stone, etc.).

3. Water

Fishkeeping in rural areas mostly uses well water. Well water is rich in minerals and trace elements, and has relatively few toxic substances, so it can generally be used without special treatment (but pay attention to pH, which varies greatly between regions). In cities, tap water is mostly used. Because tap water contains more chlorine, and chlorine is very harmful to fish, it needs to be aerated before use (that is, adding oxygen with an oxygen pump), the purpose being to remove as much chlorine from the water as possible. You can also use an open-mouthed container to age the water; the principle is the same. In my personal experience, aeration generally takes 24 hours, while natural water aging takes about 3 days to a week. Put the aged water into the tank (generally use potassium permanganate to disinfect the fish tank), heat it, and filter it. If you are keeping high-grade fish, you also need a tank-running-in process, which means first keeping some low-grade, healthy small fish in the new tank, the purpose being to let these fish's normal metabolism establish a good biochemical environment in the water. So running in the tank is actually cultivating the water. Once the water quality is good, you can put in your beloved fish.

4. Fish

When choosing adult fish, generally choose healthy individuals with bright colors, gorgeous patterns, strong appetite, liveliness and activity, and boldness without fear of people. You should also pay attention to observing whether the fish's feces are normal, and whether there is white feces or trailing feces. Also, whether the fish, besides being lively, rubs against the tank, and so on. When choosing juvenile fish, generally choose those with a moderate size, well-proportioned body parts, strong appetite, liveliness and activity, and so on. In this regard, many fishkeepers are very experienced, so I won't say more.