Greetings to you, dear visitors and readers of the blog, with you, as always, Andrei Selitsky and I are ready to share with you another useful post. A post today will be the second part of the aquarium water. If someone has not read the first, you can familiarize yourself with it here.
Today, my Internet plow is excellent, so the article was published on time and without any delay. And so, we went further to deal with the aquarium water in more detail.
The last time I described the most basic things, and today I will somewhat delve into this topic in order to reveal it in full.
In fact, the life of various organisms under water is somewhat different from the life of organisms living on land. Rather, not a few, but rather significantly. There are limiting factors in water that are simply not present in the airspace and living beings have never encountered them at all.
One of these factors can rightly be considered an active reaction of water. In sea water, this indicator practically does not change at all, however in fresh water, the active reaction indicator constantly changes and depends on the seasons of the year or the time of day.
This indicator will even differ in different layers of water.
So what is this active reaction? As you know from the school chemistry course, the H2O water formula is Buryak4 🙂 A water molecule consists of a pair of hydrogen atoms and one oxygen. Partially, water molecules will decay into ions under the influence of weak electricity.
Chemists call this process dissociation, have you heard about such a matiuk? I am sure that they have heard) Alkali, salts and acids will also break down into similar ions.
In cases. when the number of those and other ions is about the same, such water is called neutral. The neutral medium will correspond to the dial 7 on the hydrogen ion.
We know this level as pH.
The scale of the active reaction has as many as 14 points, where the number 7 is just in the middle, that is, the neutral level. If the rate of the active reaction is less than 7, then this water is called acidic, and if more than 7, then alkaline.
Sea water has a pH of 8.0 – 8.3. In fresh water, this indicator fluctuates more strongly, but in principle the entire scale is completely unnecessary.
Life in water can exist in rather large limits: 3.5 – 10.5. Some aquatic plants in the course of their life (photosynthesis) can slightly alkalize the water, and especially the surface layer right up to 11 pH.
In such cases, the fish will go to the deeper layers of the reservoir where the pH level will be significantly lower than on the surface.
If a similar situation occurs in a natural body of water, then the pH level will be constantly equalized due to the regular mixing of water. In aquariums, if you have neither a filter nor an aerator, then be in trouble.
Without constant mixing of water, meaning vertical mixing, in the upper layers of water the pH level will be very high and it will negatively affect aquarium plants – their tissues will begin to break down. Basically, the pH level in aquariums varies between 6 and 8, and if the aquarium has not been cleaned for a long time, then it can generally drop to 5 pH in the bottom layer.
The pH level will constantly change, and the softer the water in the aquarium, the higher the pH will be. This indicator will depend primarily on the mobility of water in the aquarium, lighting and plant life.
Since the pH value in aquariums will constantly change, no one can accurately determine it. During the day, the pH value will fluctuate either two units up or two down, so it seems a little ridiculous when they say that this fish needs a pH of 5.4.
This you can never determine, even in the bank in which there are no plants at all. But even in this case, it cannot be said with certainty that the pH level measured in the morning will remain at the same level throughout the day.
Let’s decide how the pH will change in the aquarium for 24 hours. When hydrobionts breathe, they absorb oxygen and release carbon dioxide.
As a result of this, energy is generated, which is so necessary for normal life activity. When carbonic acid enters the water, the water will acidify.
It turns out that any hydrobiont during respiration will contribute to acidification of water in the reservoir.
Especially this moment is very noticeable at night, when aquarium plants stop their photosynthetic activity and do not absorb carbon dioxide. In the daytime, the plants renew photosynthesis and actively consume carbon dioxide and water.
So, we decided that at night the pH will creep towards acidic water, and during the day towards alkaline. Now let’s figure out how to compensate for pH drops in an aquarium:
- Experienced aquarists have not completely changed the already established water, and replace only one-fifth. Replenished water instead of evaporated will not allow the pH level to jump back and forth. If the water in the tank is hard enough, then in fact this problem should not be.
- Another effective way to prevent pH jumps is to continuously aerate the water in the tank. The fact is that in the air bubbles that enters the aquarium, there is all the same carbon dioxide. That it will be food for plants in the aquarium in the daytime.
For all the inhabitants of the aquarium there are so-called pH-barriers, the excess of which is fraught with undesirable consequences for aquatic organisms. It is also unacceptable to move aquarium fish from an aquarium with one pH level to a jar with a value different from the initial one.
If the difference in pH levels is at least 0.8 -1, then the fish may have a shock, and aquarium plants may quickly or slowly break down tissue.
So what can happen to the inhabitants of the aquarium, when the pH is close to its barrier? These changes are very problematic to catch, but you should know about them.
We all heard about the phenomenon of the incompatibility of plants, is not it? But, it turns out in incompatible plants in aquariums simply simply does not happen, there are simply plants that have different pH barriers.
Here, for example, a plant like kabomba stops its photosynthesis when the pH level rises to 8 units, and the vallynerium holds up to 10 pH, the elodeum to 11 pH. It is clear that the starving kabomba will no longer develop its stems at the top, and only then will it be in a small way to drop its leaves below.
In Vallisneria, the leaves will also begin to wither, namely, their tips that are near the surface. Elodea will alkalify the water so that both of the above plants in the upper layers of the water will not withstand such tension.
Complex plants are difficult to maintain and care for, since their pH barriers stand side by side – in natural reservoirs such sharp changes in the pH level do not occur, unlike in an aquarium environment where there is still water.
As a rule, lowering the pH level will cause an increased appetite in the fish. However, do not rush to rejoice in this factor, just the food in the body of fish is poorly absorbed, so they devour as undermined. Some species of fish, for example, barbs, begin to vigorously swel at the aquarium soil and pebbles.
Then, the level of oxygen consumed by the fish is significantly reduced, and on the approach of suffocation. There are cases when the pH level is artificially lowered. This is done to ensure that many types of haracings begin to spawn.
Only this is done for a short time, and keeping fish in acidic water is fraught, especially for small things, pot-bellied.
As you already understood from the read, life in water is a complex thing and the influence of an active reaction (pH) is only the tip of the iceberg. The life of aquatic organisms also depends on the redox reactions occurring in the aquatic environment, or, if it is easier to call it, redox-danced. Oh potential j
What is this thing? Now we know that the redox potential can inhibit or stimulate the development and growth of hydrobionts.
When we talk about gases dissolved in water, molecular oxygen is implied, which contains a pair of atoms of this gas. It is molecular oxygen that will be captured by hemoglobin in the blood when the animal breathes.
This incomprehensible word itself emerged from two more understandable ones: reduction (reduction) and oxidation (or oxidation). During reductive and oxidative reactions, the electrical potential of the substance being reduced or oxidized changes. When one substance gives up its electrons, it will be charged positively and, as a result, it will oxidize.
And when a substance acquires electrons, it is charged negatively and naturally recovers. This is exactly the potential difference that is the redox potential.
In electrochemistry, this value is called Eh and is measured in millivolts.
When the concentration of components capable of oxidizing is higher than those that can recover, the redox potential will be higher. Chlorine, oxygen always try to accept electrons and they have a fairly high electrical potential, and it turns out that not only oxygen can oxidize, but other substances (for example, chlorine), and a substance called hydrogen will be very willing to distribute its electrons to the right and left, and they as a result have a low electrical potential.
It turns out that in the water constantly, every second, redox reactions occur, which we simply do not see, but they exist. When oxidation occurred in an artificial reservoir, such as an aquarium, inorganic substances are connected to the general crowd. When an aquarist populates a reservoir with plants, fish, snails, the oxidation processes are only intensified.
This process involves the rotten roots of plants and their leaves, the excrement of hydrobionts, the mass appearance and the death of various bacteria. For this reason, the redox potential is extremely high in a newly launched aquarium.
After that, inorganic compounds and substances, whose role in the redox process is useless in the redox process, mainly fall out of the entire vicious circle of oxidizable substances.
In biochemistry, the magnitude of the redox potential is not indicated as electrochemistry, and has the form rH (or reduction Hydroqenii). There are special tables for converting millivolts into conditional parameters rH.
In the scale of conventional units 42 divisions: 42 is pure oxygen, and 0 is hydrogen. It is clear that if the indicator of the redox potential is located next to these figures, no plant will be able to live in such water.
In natural reservoirs there is an optimum range of rH: 25-35 units. In aquariums, these parameters can jump 26-32 units.
There are plants that can withstand a relatively small indicator of the redox potential (cryptocorynes can withstand 25-6 units). The highest level of rH can sustain a geterantera – 32 units.
As it turned out, the values of rH and pH are very closely related. Oxidative processes occurring in water will lower the active reaction of water (the higher the rH, the lower the pH), and vice versa. The redox potential indicator is very difficult to measure, and this is done by quite complex and extremely rare instruments on which platinum electrodes are mounted. Unfortunately, such gadgets for aquarists are virtually inaccessible.
When measuring, you can determine the gas pressure and the concentration of the reducing form of hydrogen.
At this point I will finish my story about the properties of aquarium water. This is not the last post on this topic, there will be more interesting materials, but for now for now this will be enough for you. In the future we plan to post in which I will talk about water hardness and what it affects.
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