How often is it most appropriate to change the water when keeping fish at home?

The busyness of work and the fast pace of life have given rise to a lifestyle in which, while pursuing quality of life, we also look for ways to relieve our own stress: for example, some people use spare moments to work out, travel, go fishing, or keep a few small goldfish themselves. However, there are quite a few tricks to keeping fish, and for those who do not understand fish keeping, it really is not an easy thing. For example, we often run into all kinds of different problems, such as when it is appropriate to change the water for the fish. Below, Qinnongwang gives everyone an answer to this question.

How often should you change the water when keeping fish at home?

Generally speaking, when the weather is relatively cold in winter, the water in the tank will not need to be changed so quickly, so it does not need to be changed as often as in summer. When we notice that the fish begin to float to the surface and gulp air with their mouths wide open, it means the water in the fish tank is already low in oxygen, and at this point we need to change the water. We can also grow some beneficial aquatic plants in the fish tank; through photosynthesis they can add oxygen to the water. In addition, when changing in new water, pay attention to the temperature difference of the water. The temperature difference must not be too large, otherwise the fish will be very uncomfortable and become ill.

What kind of water should be used when changing water for fish kept at home?

1. Raw water: Raw water refers to tap water or well water that has just been drawn and has not been left to stand and age. Its water temperature often differs greatly from the water temperature in the fish pond, and it contains a relatively large amount of chlorine. This kind of water is extremely harmful to fish.

2. New water: New water is tap water, well water, or spring water that has been left to stand and settle for about 2 to 3 days, and is clean water whose temperature is equal or similar to that of the fish pond.

3. Old water: Old water is the dirty water at the bottom of the fish pond that contains excrement and filth, including water that has been used for raising fish in the pond for a long time without being changed.

4. Green water: Old water contains relatively more suspended green algae, and these are also very good supplementary feed for fish. This kind of water has less decomposed organic matter and more dissolved oxygen. Fish are often raised in clean old water that is tender green in color. Fish raised this way have the strongest appetite, are robust in body, bright in color, and develop very quickly.

5. Reverted clear water: If the old green water in the original pond is suddenly found to have turned clear, with a lot of green algae settling to the bottom of the tank, this phenomenon is called reverted clear water. This kind of water easily causes fish disease and must be completely replaced.

Methods for changing water when keeping fish at home

1. General water change: Under normal circumstances, especially in hot summer, as long as you persist every day in gently siphoning out 1/10 to 1/5 of the excrement and dirt at the bottom of the fish pond (tank) together with the old water using a rubber hose, removing dust on the water surface and floating excrement, then slowly adding new water of the same temperature along the wall of the pond (tank), the water quality can be kept clean. This water-changing method is not likely to injure the fish, and the method is simple and safe. It is most suitable for family fish tanks or small ponds.

2. Partial water change: Partial water changes are mainly carried out in two situations.

① In hot summer and early autumn, if the water in the fish pond (tank) has been changed only a few days ago, yet the water color turns green very quickly (because the amount of feed given is on the low side), and the water quality is still clean, then in order to prevent the fish from scalding their tails, you can scoop all the fish out of the pond (tank), then stir the water in the pond (tank) in a spiral, wait for a moment until it settles, siphon off 1/3 to 1/2 of the dirt and old water from the center of the pond (tank) with a rubber hose, then add new water of the same temperature and the same amount, and then scoop the fish back into the original pond (tank) to keep.

② If the water in the pond (tank) has only been changed a few days ago and the water color is still good, but floating head occurs because too much food was fed that day, emergency measures must be taken. The method of changing the water is the same as described above. If it is a large fish pond at a fish farm, there is no need to scoop the goldfish out; instead, use a folding barrier net to confine the fish to one side, then gently rotate the water in the pond with a dip net for several tens of seconds, wait a moment for the water to settle, then open the drainage gate to slowly drain the water or use a suction tube to remove the excess fish food, excrement, and old water from the center of the pond (tank), or use a fish net to scoop out the excess fish food from the center, then drain off 1/4—1/2 of the old water, and finally add the same amount of new water at the same temperature. This method is commonly used as an emergency measure at fish farms or at home when too much food has been fed.

3. Complete water change: A complete water change is often a water-changing method carried out together with emptying and cleaning the pond (tank) and selecting young or adult fish. It is usually adopted only when the water quality has seriously deteriorated, the moss has grown too long, or the fish are too crowded.

① When there is no spare pond available, you have no choice but to scoop all the fish into a basin or put a net cage into the water of an adjacent pond for temporary holding, and add an oxygen supply head to the basin or net cage to increase oxygen. Then, scrub off the moss on the walls of the original pond, rinse it thoroughly and clean it, then refill it with new water of the same temperature, let it stand for a moment until the water temperatures are equal, and then scoop the fish back into the original pond (tank).

② If there is a spare pond and new water available, then you only need to scoop all the fish into a basin or net cage, select and handle them separately, and separate into different ponds where needed; those not being separated can be moved into the new water to keep once the water temperatures are equal. With this water-changing method, special attention should be paid to water temperature, and it is best to do it before 9 a.m. on a clear day. However, this method is generally only suitable for adult fish or relatively large young fish, and should not be used for fry. If conditions permit, before a complete water change, you can first fill a spare pond (tank) with aged water, and then scoop the fish directly into the spare pond (tank), which is better. In this way, the water temperature changes little, the fish are more likely to adapt to the new environment, and the fish are spared the suffering of being crowded in a basin or net cage. With this water-changing method, in spring and autumn it is generally carried out once about every half month. In the hottest summer weather, when the water temperature reaches above 28°C, when the water color very easily becomes dense and the water quality very easily becomes turbid, a complete water change should generally be carried out once every 5—7 days. In winter, when the water temperature drops to around 4°C, the fish move slowly, their appetite decreases, and the water quality is not easily spoiled, so unless there are special circumstances, the water is generally not completely changed.

After reading this article, do you feel that keeping fish is also quite a bit of knowledge? The knowledge involved covers all aspects. While keeping fish brings us pleasure, it also lets us learn the relevant techniques. At the same time, we should pay even more attention to some related details, so that the fish can be kept lively and vigorous and be more pleasing to the eye to watch.