1. Tap water: Tropical ornamental fish are generally suitable for weak acidic or weak alkaline soft water. Tap water is almost neutral and suitable for tropical ornamental fish. However, due to the use of bleaching powder, the free chlorine produced in the water body must be removed before it can be used. There are two ways to remove chlorine: one is aeration: put water into a storage bucket and leave it indoors for 4 ~ 5 days or 1 week. The specific time should be flexibly controlled according to the water temperature and the requirements of fish for water quality. Low chlorine content, high temperature, strong fish adaptability and short aeration time, and vice versa. If there is air stone pumping air, it will be more conducive to chlorine removal; The second is chemical dechlorination. Tap water is put into a storage bucket, sodium sulfide (baking soda) is immediately added (generally 10kg water is added 1g baking soda), and the dechlorination can be achieved by stirring to dissolve it evenly. Third, it is more reliable and safer, and you can also buy dechlorinated water directly from the market. In production, manufacturers add water quality stabilizers to ensure water quality.
2. Natural water and well water: Use natural water (lake water, river water, etc.). ) you should cook tropical fish first. Boiling can also reduce the hardness of water for sterilization, but because the oxygen in boiling water and distilled water has been greatly reduced, it needs to be aerated and oxygenated before it can be used for breeding.
Second, the water temperature.
1. water temperature: fish is a kind of temperature-changing animal, and it will change its body temperature according to the environmental temperature. Each tropical fish has its own suitable temperature range. Once the water temperature changes drastically or inappropriately, the body function of fish will be out of balance, leading to fish diseases. Generally, the water temperature of tropical ornamental fish at home is 22 ~ 26℃, and the water temperature of aquaculture is 26 ~ 30℃, depending on the species of fish.
2. Temperature difference: When cultivating tropical ornamental fish, the temperature difference between day and night shall not exceed 4 ~ 5℃, and the temperature difference between day and night during breeding period shall not exceed 1 ~ 2℃. This requires that under the same water temperature, spare fresh water should be placed near the aquarium for preheating and then injected into the aquarium to prevent fish diseases caused by excessive temperature difference.
3, temperature control: Aquarium should pay attention to adjust the water temperature, it is best to use automatic constant temperature electric heating tube to control the water temperature, whether it is feeding period or breeding period, we should pay attention to adjust the water temperature to a suitable area, according to the temperature required by tropical fish to control the water temperature. Rough classification: (1) low-temperature resistant water temperature can be controlled at about 20℃; (2) It is not suitable for low temperature, and the water temperature can be controlled at 22 ~ 24℃; (3) Like high temperature: it can be kept at around 26℃.
Third, the water quality:
1. Hardness and adjustment: Although tropical fish have different hardness to water, they can tolerate large hardness changes and are not as sensitive to hardness changes as temperature. Generally, the hardness of varieties with strong adaptability to water quality can not be adjusted, but in the breeding period, the hardness of water should be adjusted to meet the requirements of tropical fish breeding. It is necessary to determine the hardness of water before adjusting its hardness. Generally, it is tested by a hardness tester (x ml of water is injected into a graduated test tube, and the titration solution is added dropwise until the color in the test tube changes, and the hardness is calculated by the number of titrated drops).
Reduce the hardness of water:
(1) Boiling water is often used to reduce hardness; The amount of water added is different from pure water. Because boiling water can only eliminate carbonic acid compounds and reduce temporary hardness, but can't remove sulfuric acid compounds and chlorides, but reduce permanent hardness, boiling water can only reduce hardness 1/3 ~ 1/2. For example, the hardness of water is 20 degrees, the required hardness is 10 degrees, and boiling cooling water is enough.
(2) Activated carbon adsorbs metal ions in water, which reduces the hardness of water and also has the function of sterilization and deodorization. The hardness of water can also be reduced by putting activated carbon into the water of the filter and repeatedly passing the water to be adjusted through the activated carbon.
(3) Adjusting hardness by proportioning method: adding soft water into raw water to reduce the hardness of raw water.
2. pH and adjustment: pH has a great influence on the normal growth of tropical fish, which is too acidic, making it difficult for fish to breathe, increasing a lot of biotoxicity; The gill tissue of fish with excessive alkalinity is corroded, which affects the normal growth. To adjust the pH value of water, it is also necessary to measure the pH value of the water to be used (that is, the pH value is measured by a pH tester). If there is a big difference between the pH value and the pH value of water needed for breeding varieties, acid sodium bicarbonate solution (1% solution) is added to improve the pH value; Add sodium dichlorophosphate solution (1% solution) to lower the pH value. During operation, fully stir gradually, and test with pH tester from time to time until the pH value of water meets the requirements. It should be noted that the pH should be controlled within the range of 0. 1pH, and the drastic change of pH is also unfavorable to tropical fish. Avoid adding more sodium bicarbonate and sodium dihydrogen phosphate, and add more sodium bicarbonate to sodium dihydrogen phosphate.
3. Dissolved oxygen: In tropical ornamental fish culture, if there is no oxygen in the water, tropical ornamental fish will appear "floating head" phenomenon, and if measures are not taken immediately, the whole tank of fish will often die. Generally, the dissolved oxygen content is greater than 5.0 mg/L, which is the suitable value for fish survival. Between 3.0 and 4.0 mg/L, fish can hardly survive; 0.3-2.9mg/L, which is not suitable for survival (oxygen content in water can be tested with O2 testing agent). Increasing the content of dissolved oxygen in water can be achieved by reducing water pollution, increasing illumination time, equipping with oxygen-increasing devices, increasing the number of water changes, reducing the number of fish and filtering the water in the aquarium.
4. Nitrite (NO2) When the ecosystem or oxidation chain of bacteria is destroyed, nitrite (NO2) will be produced in the water due to the decay of excrement and food submerged in the water. NO2 is highly toxic, but tasteless and colorless, which can't be distinguished by naked eyes. When NO2 reaches a certain amount, it will poison the fish in the aquarium. In order to prevent the NO2 content in the aquarium from exceeding the standard, the following methods are usually adopted:
(1) Install the filtration system and add biochemical filter materials, such as biochemical filter balls and ammonia absorption filter materials. (2) Adding artificial active nitrifying bacteria to make the water have nitrifying ability and reduce the toxicity of nitrite. (3) Reduce the number of fish farming and change water regularly. (4) Adding water quality stabilizer. (5) Adding photosynthetic bacteria to adjust the water quality and suck out the remaining residual bait in time.
4. Changing water: In the daily management of tropical ornamental fish, it is very important to maintain good water quality, and the most direct way to control the stability of water quality is to change water to dechlorinated tap water, which is more in line with the requirements. The frequency and time of changing water depend on the feeding conditions and the species of fish. If the aquarium filtration system is perfect, the number of fish is appropriate, and the aquarium is well managed, a small amount of water can be changed every week, and then all water can be changed from several months to half a year or 1 year. But if the management is not good, it is necessary to increase the number of water changes. It should be noted that if the water quality is not seriously deteriorated or the fish is infected with infectious diseases, it is best not to change all the water, because it is difficult for tropical ornamental fish to adapt to the sudden change of water quality.