Any of you at least once during the period of practicing aquaristics faced such a problem as the flowering of water. In many editions and advice of advanced aquarists, there is an opinion that darkening the aquarium for a few days, more precisely for 5 to 7 days, will save the aquarium from this trouble, like greenery. All this is certainly so and as they say in many ways correctly. But unfortunately not always it helps. That is, after you open the aquarium, after darkening the water really becomes crystal clear. However, in some cases this is not for long. After 2 - 3 days the water begins to grow turbid and acquire a green color (and this, we want to note, not only in the summer, sunny months, so the discount on sunlight is not always justified).
Of course, you can also use the well-known method to resort to daphnia. You can try, by the way, many like to do it often - but in vain, the introduction of chemicals into the water. But about this you must have read somewhere or heard somewhere. Now back to where we started.
So once again we recall that not always darkening the aquarium for 5 - 7 days helps in combating the flowering of water (by the way, the flowering of water does not necessarily happen in the summer, as it is commonly believed). So, the best way to deal with this kind of struggle with the flowering of water, we mean the blackout, at the same time add some more additional ways:
- to feed fish during the darkening period every three days, very little (or not to feed at all, nothing will happen to them in such a short time, however, as well as with aquarium plants that will be left without light for the same period);
- do not change the water in the period of darkening in the aquarium (do not allow the algae that is spread in the water (and the flowering of the water is microscopic algae) to eat normally, ie to take from the water the substances necessary for their life.
- can also be added to the filter in the form of turf crumb filler, so that it acidifies the water (by the way, this method can be tried without shading the aquarium, it also helps), but do not forget that some fish do not tolerate the pH change very well.
After the end of preventive measures, it is necessary to carefully soil the soil, clean the walls of the aquarium and rinse the filter, change 1/5 of the water. If peat was used as a filler, it can be returned to the aquarium for a while beforehand (pay special attention to the behavior of fish, when using peat chips).
Algae can develop massively if there are a lot of organic substances in the water. For the mass development of plant organisms, an optimal combination of various factors is necessary. This is a sharp daily fluctuations in the amount of oxygen in the water, as well as acidity and rigidity. Of great importance is the temperature and especially the lighting. The flowering of water is promoted by the decomposition of food, in the aquarium and the presence of metabolic products.
The duration of mass development of plant microorganisms is different. Usually the water blooms in the aquarium in bright sunlight and with strong artificial lighting no longer than three weeks. In summer, green and blue plant microorganisms predominate, in the winter - silicon ones.
But is the water so dyed harmless, as it is often said and written? During flowering, an excess of oxygen is formed in the water, which has a detrimental effect on fish, especially during breeding and during frying of fry. With mass development, plant organisms absorb the light needed by higher plants. Sometimes, when the water in the aquarium blossoms, all the plants die.
You can fight against the flowering of water in the aquarium in several ways. In some cases, it is enough to filter the water. In others - to destroy very small plant microorganisms it is recommended to put large daphnia into the water. Decrease in temperature and decrease in illumination are also very effective ways to combat the flowering of water in the aquarium.

Sent by Valera Bogatyrev in Orenburg