What is the difference between the upper circulation and the lower circulation of an ecological fish tank?

Raising water is the most important and tiring thing in fish farming. Raising water can bring the best water to fish-water with self-purification ability. Answer here what is good water with self-purification ability! Due to the complexity of the theory, I will first give some simple indicators of artificial water saving:

1. After fish have lived in water for two weeks, the water is still clear, transparent, colorless and tasteless;

2. An internal large circulating water system maintained by a powerful biochemical filtration system;

3. The system has a complete flora that decomposes organic matter; Heterotrophic bacteria decompose organic matter into ammonia;

4. There are perfect ammonia decomposing bacteria in the system; -Nitrifying bacteria Nitrite bacteria decompose ammonia into nitrite;

5. There are complete nitrite decomposing flora in the system; Nitrifying bacteria Nitrifying bacteria decompose nitrite into nitrate;

6. The system has a complete flora that decomposes nitrate; -Anaerobic bacteria decompose nitrate into nitrogen and volatilize it.

After the above steps are completed, fish excrement is completely decomposed within 24 hours, and the content of toxic substances (mainly ammonia and ammonium, excreta from fish) in water can be kept at a very low level for a long time, which is lower than the average level of changing water every day!

You should have:

1, a big fish tank, used for landscaping and fish farming-it depends on your financial resources and wisdom;

2. A set of filtration system for fish farming, using a large number of glass biochemical circles or medium-sized sand as filter materials, pumps, lamps, etc. If the total water consumption of fish farming is 1 00L, then you need sand with a diameter of 3 mm above10L as the filter material or at least1L as the glass ring, a water pump with a flow rate of more than 500L/h and a set of water circulation pipes to make the water flow good so as to suck feces. This depends on your financial resources and learning ability. At the fish culture forum,

3, a set of biochemical filtration theory-this is in the following article. (Reprinted and abridged)

Many fish farmers have some misunderstandings about nitrifying bacteria. Some people think that nitrifying bacteria can decompose feces. Some people think that water quality can be purified and suspended solids in water can be neutralized, but these understandings are inaccurate. Let's talk about the understanding of nitrifying bacteria, and hope you can correct me. 1 first of all, let's talk about decomposing organic matter, which is not made by exquisite nitrifying bacteria, but by other water-purifying bacteria. In the aquatic ecological circulation system, if there are no other heterotrophic bacteria, the water will be full of organic matter that has not been decomposed by bacteria, and this self-polluted aquarium environment will make fish unable to survive. Therefore, they are often regarded as Depth Charge with self-purification of water quality, and their importance is no less than that of nitrifying bacteria. This kind of bacteria is ubiquitous in all kinds of environments, and its reproduction speed is quite amazing. In an ideal environment, most heterotrophic water-purifying bacteria can multiply twice by themselves in only a few tens of seconds, usually only 20 minutes. But if it is raised in a bare tank, we will suck the remaining bait or feces out of the water by physical circulation. -They should have sand to live in! This culture method relies on the natural decomposition process of dead fish.

2. About purifying water and neutralizing suspended solids in water. Many netizens who raise fish buy nitrifying bacteria and add them on time every week according to the instructions. Is this right? The answer is absolutely correct 100 points. But the so-called nitrifying bacteria I add every week are actually photosynthetic bacteria.

Photosynthetic bacteria, commonly known as B bacteria. Photosynthetic bacteria is a microorganism in water, because its photosynthetic pigments are pale pink, including bacterial chlorophyll and carotenoids. Photosynthetic bacteria can use the hydrogen in the compound to carry out photosynthesis without producing oxygen under anaerobic and light conditions.

Photosynthetic bacteria can survive in polluted environment and play an important role in purifying water quality. But only when the living environment and pollutants conform to their physiological and ecological characteristics will they play a role, otherwise it will be difficult to obtain expectations. For example, in the absence of light or oxygen, photosynthetic bacteria are difficult to play a role.

If there are photosynthetic bacteria in the aquarium, it will absorb and utilize substances such as organic matter or hydrogen sulfide, which will weaken oxygen-consuming heterotrophic microorganisms due to lack of nutrition, thus reducing the chance of toxic decomposition products and purifying the water quality in the sediment, thus promoting the healthy growth of cultured aquarium organisms.

At present, the photosynthetic bacteria sold in the aquarium market are mainly Rhodosporidae, especially Rhodopseudomonas. This photosynthetic bacteria can effectively purify water quality in different metabolic ways under different environmental conditions. It should be noted that photosynthetic bacteria work best in the environment with water quality of ph8.2-8.6, so they are more suitable for use in seawater aquariums. So photosynthetic bacteria can only have a short-term effect, because there is no ideal environment for him to survive in our fish tank. Unless we make an anaerobic filtration zone and have lighting.

Nitrifying bacteria and "nitrogen compound cycle"

1, when it comes to nitrifying bacteria, I have to say it again. If you want to understand nitrifying bacteria, you must first understand what nitrogen cycle is, so I will draw a sketch below, hoping to help you.

Step one:

Fish excreta and uneaten food (such as fish blood) will be converted into ammonia (commonly known as ammonia); That's because the bacteria that need oxygen in these things will decompose protein. Ammonia is poisonous.

Step two:

Nitrifying bacteria living in oxygen can transform ammonia into nitrite (NO2); Although nitrite contains less toxins, it is still fatal to fish.

Step 3:

Nitrite was later converted into nitrate (NO3) by the second nitrifying bacteria. This nitrate is almost nontoxic, but sudden or long-term exposure to high concentrations of nitrate is harmful. Fortunately, the concentration of nitrate can be reduced by changing the water in the fish tank.

Step 4:

If water is not changed, nitrate will be transformed into nitrogen and sublimated by bacteria (anaerobic bacteria) that live independently of oxygen. This step is called "biological denitrification", and it is a complete "nitrogen compound cycle" from 1 to 4.

2. What is nitrifying bacteria?

Nitrifying bacteria, commonly known as nitrifying bacteria, is an aerobic bacteria, which can grow in aerobic water or sand and play an important role in the process of nitrogen cycle water purification. They include bacteria, cocci or spirochetes with different forms. It belongs to a kind of autotrophic bacteria, including two completely different metabolic groups: nitrosomonas and nitrifying bacteria.

Nitrite bacteria are generally called "ammonium oxide bacteria" because their only food source is ammonium, and the chemical energy produced by ammonium and oxidation is enough for them to survive. What is ammonium? This needs explaining. In fact, ammonium is a cation (nh4+) generated when ammonia (nh3) is dissolved in water. Because it behaves like a metal ion chemically, it is named "ammonium". Gaseous ammonia has a pungent smell, while ionic ammonium has no special smell and is easy to identify.

Ammonium can be absorbed and utilized by nitrite bacteria in the presence of air. They oxidize their hydrogen atoms into water and replace them with oxygen, so that ammonium becomes water and nitric oxide dissolves in water. The latter is called "nitrous acid" by chemists, and its reaction formula is as follows:

Oxygen can generate energy by oxidizing ammonium into nitrite (no2-), and nitrite bacteria can use this energy to generate organic matter from carbon dioxide or alkalinity (such as co32- or hco3-), so such bacteria can survive and reproduce without organic matter at all.

Nitrogen-containing bacteria are generally called "nitrite-oxidizing bacteria" because the main food source for their survival is nitrite, and the chemical energy generated by the reaction between nitrite and oxidation is enough to make them survive, and the generated nitric acid is the final product of nitrogen cycle. The reaction formula is as follows:

Nitrogen-containing bacteria can use the energy generated by this reaction to synthesize the organic matter they need, so these bacteria can survive and reproduce without ingesting organic matter.

Ammonium is oxidized by nitrifying bacteria to nitrous acid and then to nitric acid, which is called "nitration reaction" by chemists. This reaction is carried out by two different bacteria, which need to cooperate closely to prevent the accumulation of no2-, the intermediate product of the reaction, in water.

3. How to increase enough nitrifying bacteria?

The toxic substances in the culture tank are mainly ammonia and nitrous acid, which can be consumed by nitrifying bacteria and produce nontoxic nitric acid. It is the best nitrogen fertilizer for algae and can be absorbed and assimilated by algae. Therefore, nitrifying bacteria are absolutely indispensable in the culture tank. Without nitrifying bacteria, the ammonia content in the water will increase rapidly, leading to the death of fish in the pool water. Many people usually don't understand the importance of this problem, so that they often encounter the fate of aquaculture failure. This shows that even experienced operators may be defeated by the lack of nitrifying bacteria if they do not understand the crux of this problem and seek improvement.

From the ecological point of view, we can't stop the production of ammonia, but we can try to increase the number of nitrifying bacteria to consume a lot of ammonia in the pool water. Because nitrifying bacteria are the bane of ammonia consumption, as long as the number of such bacteria is enough, it will naturally consume the ammonia produced every day, so that ammonia will not accumulate in large quantities in water and become the invisible killer of aquaculture.

What should be done to increase the number of nitrifying bacteria? Theoretically speaking, creating an ideal breeding ground for nitrifying bacteria is the most fundamental solution. How can I put it? It turns out that nitrifying bacteria are easy to attach to the surface of fixed objects during reproduction. If a plurality of fixing devices with multiple surface areas can be put into pool water for attachment, it can quickly attach to the surfaces of these fixing devices and begin to proliferate.

However, it is usually not feasible to place fixtures in the pool water, because this way may hinder the activities of fish and is not conducive to fishing. The feasible treatment method is to place suitable filter materials in the filtration system. This product is specially designed to provide breeding ground for nitrifying bacteria, and it usually has a large surface area for nitrifying bacteria to attach. Its principle is to turn nitrifying bacteria into "snails with shells" and increase the living space of nitrifying bacteria. Therefore, nitrifying bacteria can attach to this artificial object for nitrification, so that ammonia and nitrite in the filtered water are consumed by nitrifying bacteria.

Adding nitrobacteria preparation is another feasible method, especially when the water quality test finds that the ammonia concentration in the water is high, this method has the highest efficiency. However, this method only treats the symptoms, not the root cause, because these preparations are still mostly "shell-less snails" after activating viable bacteria in water, which cannot proliferate in pool water, and even gradually die due to environmental discomfort. They must be added regularly to play the expected effect.

4. How to use the filter correctly?

Commonly used are special filter materials such as glass rings and ceramic rings that remove ammonia by biochemical methods, and the most common filter material is sand. However, they do not remove ammonia through the function of the filter material itself, but transform ammonia into non-toxic nitric acid through nitrifying bacteria living on the surface of the filter material, thus reducing the accumulation of toxic substances and creating an excellent growth environment for cultured organisms.

5, the use of nitrobacteria preparation

Nitrifying bacteria preparation is a kind of treatment agent used to control the concentration of autogenous ammonia in aquaculture pond water. It is not only convenient to use, but also has an immediate effect, so it is more and more popular among fishermen. When in use, the agent can be directly dispersed in the pool, and the ammonium removal effect can be quickly exerted.

Commercial nitrifying bacteria preparations can be divided into living bacteria and dormant bacteria, and fish friends can choose to use them according to their own needs. The former is made of living bacteria, and their activities can be seen under the microscope. The latter is made of dormant bacteria, but they can't be seen under the microscope.

The advantage of selecting live bacteria is that it can remove ammonium quickly, which is most suitable for emergency situations with high ammonia concentration. However, living bacteria have strict requirements for oxygen, especially nitrifying bacteria, which can only survive under the condition of sufficient oxygen, so it is often difficult to preserve living bacteria and make products. Therefore, when buying such products, we should pay special attention to their effective service life. If we use expired products, it is inefficient from the point of view of ammonium removal.

The advantage of choosing dormant bacteria is that they can be preserved for a long time without worrying about failure. However, because the activation time from dormant bacteria to live bacteria may take several days, it can not be used for emergency treatment, but only for daily water quality management. Generally speaking, the shelf life of dormant bacteria is about 1 ~ 2 years, so we should still pay attention to the service life marked on the goods to avoid expiration. In addition, this product can only be made into preparations by bacteria belonging to nitrite genus, so after use, there may be redundant intermediate no2- accumulated in water, which makes the concentration of nitrite suddenly increase temporarily, but it will not have obvious influence on water quality.

6. Matters needing attention of nitrifying bacteria

There are organic pollution sources in water, and water purification bacteria live on organic pollution in water. If there is no pollution source in the water, they can't survive for a long time. Therefore, it is worth discussing whether adding bacteria in the new water stage is effective.

Don't use it with disinfectant.

In order to avoid killing water purification bacteria, remember not to use it with disinfection and sterilization agents. If it is necessary to use disinfectants or drugs to treat fish diseases, you need to wait at least one week before using water-purifying bacteria.

Pay attention to adjust the temperature suitable for bacterial growth.

In the process of using water-purifying bacteria, it can be effectively controlled under the most suitable water temperature conditions, and of course its effect is also the most ideal. For example, photosynthetic bacteria can grow and reproduce normally in the range of 23-29℃. When the water temperature is lower than 23℃, their growth gradually stops, so the effect of using such bacteria in aquariums below 23℃ is poor. Generally speaking, nitrifying bacteria can reproduce and grow well at 25-30 degrees.

Pay attention to adjust the ph value suitable for bacterial growth.

In the process of using water-purifying bacteria, we must pay attention to the change of ph value of water quality. For example, nitrifying bacteria in fresh water have the best effect when the ph value is neutral, and the worst effect in acidic water. Therefore, if the water quality in the aquarium can be adjusted to neutral or weakly alkaline, its water purification effect will be better.

Pay attention to the compatibility between bacteria.

If you want to keep different water-purifying bacteria at the same time, you should pay attention to the compatibility between bacteria. For example, nitrifying bacteria and photosynthetic bacteria are not suitable to be placed in the same aquarium at the same time, because they inhibit each other in the process of purifying water, which may reduce their purification effect.

Provide enough habitable space for bacteria.

If bacteria only live in aquariums, they may not be able to meet their reproductive needs, which will seriously limit the number of bacteria and prevent them from increasing. Therefore, we should cooperate with the biochemical filtration system to create more habitable space for bacteria to reproduce, in order to expect them to accelerate the reduction of harmful substances and strengthen their decomposition ability.

Finally, it is necessary to provide sufficient oxygen for nitrifying bacteria.

Second, anaerobic bacteria and "nitrogen removal system":

1, the living conditions of anaerobic bacteria: a large number of low-flow anoxic areas, not completely anaerobic areas; Sand tank and the bottom of thick sand layer (5cm- 10cm); Neutral river sand with a diameter less than 3 mm can be selected when the sand layer is 5 cm thick, and sand with a diameter greater than 5 mm should be selected when the sand layer is 10 cm thick. Using casserole is a good choice; Put fine sand with a diameter of 2 mm into a jar with a volume of 1 liter, leaving a small gap;

2. Carbon source: In the process of biological denitrification, anaerobic bacteria need organic carbon to decompose nitrate, and the common organic carbon source is white sugar. Sand tanks can be injected regularly.

3, state, when you see the bubbles poured out of the sand.

4. Experiment, container size, filter material selection and carbon source supplement all depend on your patience.

Third, the lower biological nitrogen removal system:

1, using the high consumption efficiency of nitrate by algae and other lower organisms to eliminate nitrate in water and complete the second stage of redox process-reduction stage;

2. Using the sensitive reaction of algae to light, an independent filter tank is set in the filter equipment, and with proper illumination, brown algae, green algae and even black algae are cultured in large quantities, and nitrate is rapidly decomposed and reduced in the area where nitrate is most concentrated. So that the whole ecological filtration system becomes a closed cycle.