How Often to Change Water for Goldfish, Prices, How to Tell Male from Female, and How to Keep Them

Goldfish and crucian carp belong to the same species taxonomically, originated in China, and are also called “golden crucian carp”. Similar to carp, they are ornamental fish that evolved from crucian carp. So how often should you change a goldfish's water? How much does one cost? How do you tell males from females? How do you keep them alive? According to the Changsha flower, bird and fish market, there are many kinds of goldfish. One type, the Ryukin, is very expensive: small ones cost a few yuan, large ones over a hundred. Generally, larger fish of common varieties cost between 30 and 100 yuan each. But small fish of non-prized varieties are very cheap! The cheapest, at two cm long, is 0.5 yuan each. There are also prices ranging from 1 yuan to 10 yuan depending on the size of the fish.

How often should you change a goldfish's water?

1. How often you change a goldfish's water generally depends on your own situation. If the water is very cloudy, or the goldfish lack oxygen, change it immediately. Normally, it is once every three to four days in summer, once a week in spring and autumn, and once every half a month in winter, each time replacing one third of the original water volume.

2. For fish keepers, there are four kinds of water: first, new water, which is freshly rested tap water or freshly drawn well water. Although this water is very clean, it is very different from the environment in which fish live in nature. Because there is no nitrifying bacteria community in the water, the fish's waste and scattered food residue rot and decompose into ammonia, and the fish are very prone to poisoning. Second, old water, which is light green or pale amber, rich in humus and beneficial microorganisms and algae, and has established a good ecological circulation system; through the nitrogen cycle, it decomposes into nitrate, which is harmless to fish. This kind of water is extremely beneficial to the growth of fish. Third, green water, in which the organic matter content is too high, so blue-green algae, green algae and brown algae multiply in large numbers, the content of bacteria and microorganisms skyrockets, and the water turns a deep green and sometimes gives off a bad smell, very easily causing all the fish in the tank to die. Fourth, recovered clear water, also called biting clear water, is when the algae and microorganisms in green water are so numerous that they use up all the oxygen in the aquarium, causing the death of the algae and aerobic bacteria, turning the water into dead water that is crystal clear, oxygen-free, and full of a large amount of anaerobic harmful bacteria.

From this we can see that not all water is suitable for a goldfish's life. The water most suitable for goldfish growth is old water. So-called water cultivation is the process of letting new water transform into old water.

How do you tell male goldfish from female goldfish?

1. Look at the goldfish's abdomen

When observing whether a goldfish is male or female, many people's first reaction is to look at the goldfish's belly. If it is bulging, it means the goldfish is pregnant, and this one is a female. However, outside the breeding season, this cannot be seen. And you also have to consider whether the goldfish's belly is big because it is sick.

2. Look at the goldfish's body shape

First, we can start with the goldfish's body shape. Adult male goldfish have a slender body like a willow leaf, while the body of a goldfish is often short and fat. Put a tank of goldfish together for comparison, and you can quickly tell the males from the females based on body shape. This is an important basis.

3. Look at the goldfish's tail

Observing a goldfish's tail can also help determine its sex. Generally speaking, male goldfish grow stockier than female goldfish, especially in the tail part. The tail of a male goldfish is relatively wide and flat, clearly different from that of a female goldfish, and a careful observer can tell them apart at a glance.

4. Observe how the goldfish swims

You can also tell males from females when goldfish swim. Male goldfish swim relatively nimbly. They also swim fast, while female goldfish are more docile and swim relatively slowly.

5. Observe the goldfish's color

If you carefully observe a goldfish's appearance, the one with brighter, more brilliant colors is the male. In addition, a goldfish's color is also a sign of whether it is healthy. If the color becomes lighter, it means the fish may be in a sub-healthy state, and you should change the water or immediately switch to color-enhancing fish food. If handled early, the goldfish can recover its bright natural color in the shortest time.

6. Observe the goldfish's vent

Turn the goldfish over and observe the vent on its belly. The male's vent is narrow and long, while the female's vent is relatively large and round in shape (so it can lay eggs). This method of judging whether a goldfish is male or female is the most accurate. The editor reminds everyone to be sure to handle goldfish gently. Fish are timid, and being startled can make them sick.

7. Observe the goldfish's fins

Male fish's fins differ from female fish's and are relatively thick and strong. If a goldfish's fins are curved and relatively thick, and it also matches the above characteristics, then this fish may be male. Female fish's fins are relatively short. In addition, during the breeding season it is also good to look at the spawning stars. The one with spawning stars (small white dots) is the female.

How do you keep goldfish alive?

Food:

1. Judging from the nutritional composition of the food and the growth of goldfish, live food is more conducive to goldfish growth. For example, fish worms, bloodworms, tubifex, and suitably sized insects. Daphnia are only available in summer and autumn. Nematodes are available in all four seasons. Mealworms are relatively common, can be bought in ordinary flower and bird markets, are relatively clean, and have a high protein content, making them a relatively suitable natural bait.

2. Feeding only one kind of food is not necessarily healthy for a goldfish's physical growth. It can also eat plant-based foods, such as yellow algae, diatoms, green algae, duckweed, small duckweed, aquatic plants, bran, soybean cake, noodles, rice, bread, and so on. In addition, there are all kinds of dried foods——dried bloodworms and artificial feed.

Tips:

1. First, wash clean a transparent fish tank (other containers are also fine, but note that they must be transparent)

2. Use soda water; if you do not have soda water, you can use cooled boiled water instead. But remember never to use tap water, because tap water contains chlorine used for disinfection, and little goldfish cannot take it.

3. Use as much water as possible to ensure good oxygen content and give the fish sufficient freedom. Buying a small air pump specially for fish keeping is best.

4. If conditions do not allow you to maintain the water temperature of the fish tank, on this cold winter day you should often give the goldfish enough sunlight.

5. Put some white rice stones and some aquatic plants in the fish tank, but remember that the aquatic plants must be appropriate.

6. For feeding, you can throw in some fish worms or white steamed buns, but feed a little at a time and feed frequently.

In addition, also note that little goldfish are especially prone to white spot disease (a parasitic disease). If you find such things on the fish or see wounds where scales have fallen off, remember to go to the flower and bird market to buy a kind of ”yellow powder” (mainly for anti-inflammation), and when changing the water for the fish, drip in some methylene blue medicine (mainly for removing parasites).