Better to underfeed than to overfeed.
Most troubles can happen to aquarium inhabitants due to improper feeding. It is necessary to learn a few truths that are quite clear to experienced aquarists.
Better to underfeed than to overfeed. This is the “golden” rule of aquaristics. In the practice of aquarium fish farming, there are no known cases of fish dying from hunger. But more than half of the cases of diseases and, ultimately, death of fish are associated with overfeeding them, as well as with uncontrolled throwing of food into the aquarium water. “The hungrier the fish, the healthier they are,” joked experienced aquarists. And there is a grain of truth in this joke. And yet, even an experienced aquarist finds it difficult to resist the sight of fish rushing for food, so as not to increase the food portion.
The active desire to take food is one of the signs of fish health. Some of them (for example, young Pterophyllum) generally do not know moderation, overeat, get sick, and often even die. Those adult fish that do not die immediately become predisposed to obesity, metabolic disorders in the body, and severe diseases.
It is enough to feed adult fish once a day, preferably in the morning hours. At the same time, it is imperative to observe how the fish take the food. If the fish lose interest in the food, miss food particles past their mouth or spit it out, then feeding should be stopped immediately, and the excess uneaten food should be removed from the aquarium. Even live food not eaten by fish sooner or later dies and begins to decompose. As for dry foods, they immediately begin to rot. The water becomes cloudy and spoils. It is useful to leave adult fish completely unfed once a week (to arrange a fasting day). They can also withstand longer (up to three weeks) fasts. Young fish (fry) should be fed frequently, several times a day, but in very small portions.
When offering food to fish, you need to know what type of nutrition your pets belong to and which foods are preferable for them. And although most species of fish in the aquariums of beginner amateurs can be classified as omnivorous, eagerly eating any known foods, among them there may be, for example, those that will not live, develop, or reproduce normally without receiving a sufficient amount of plant-based foods, or vice versa, fish that do not live long (Pterophyllum) without live foods in their diet. Your pets should receive the entire, as they say, food spectrum of foods familiar to them in nature, and preferably in those ratios of plant and animal origin that are necessary for a given species.
For a beginner aquarist, in order to balance the feeding diet in terms of composition if possible, it is desirable at least to diversify the menu, not to be lazy to find the slightest opportunity to alternate foods, trying to increase the number of components. At the same time, one should adhere to the rule of using only fresh or freshly prepared foods; many types of foods prepared for future use during long-term storage oxidize and lose their nutritional properties.
Often inexperienced aquarists do not attach importance to the size of the food, not realizing that fry and fish with a small mouth cannot swallow a large larva, worm, or daphnia, and they remain hungry, while the food dies and decomposes. At the same time, large fish become annoyed at the sight of food that is too small for them. There are known cases of the death of juveniles that swallowed food that was too large for their strength and were unable to get rid of it. Of course, each species and at different ages has its own feeding characteristics. Sometimes in cramped conditions and with a lack of food, fry of some species (Trichogaster, cichlids, etc.) grow so unevenly that if they are not sorted, individuals that have noticeably outgrown their smaller brethren immediately begin to eat them.
Actually, the manner of eating, so to speak, differs in different species of fish, and accordingly the structure of the mouth and digestive organs also differs (in herbivorous and omnivorous fish, the intestine is long, and the stomach is poorly developed or absent altogether, in predatory fish it is well developed, capable of stretching and accommodating single portions of large food items slightly inferior in size to the predator itself, but the intestine is very short).
Some fish pick up food mainly from the surface, even jumping out of the water, and have an upper mouth opening, while others search for food at the bottom and are equipped with a lower mouth opening and, as a rule, have an increased sense of smell. Today, aquariums contain fish that scrape algae from stones, glass, and other objects. In these species, the mouth is equipped with a sucker and works like a scraper. All this should be known in order to be able to create familiar feeding conditions for your pets in the aquarium that correspond to their biological characteristics.
Disease is easier to prevent than to cure.
Almost all beginner aquarists are “sick” with an irrepressible desire to treat their fish. What can be said in this regard? Of course, it is a pity to see sick and dying fish. For a person with a kind heart, this is especially difficult. But here it is necessary to do everything in our power and not to undertake what is beyond our knowledge. Considering the fact that in ninety cases out of a hundred, the cause of disease and death of fish in the aquarium is not contagious diseases, but diseases caused by improper maintenance and feeding, it is most often sufficient to maintain healthy, stable conditions in the aquarium, a state of biological equilibrium, and observe other rules mentioned above so that the fish do not feel depressed and their bodies find the strength to resist the effects of pathogens of contagious diseases. Disease is easier to prevent than to cure. This rule is fully applicable when keeping fish in an aquarium.
Pathogens of contagious diseases enter the aquarium with soil, plants, water, live food, mollusks, and new fish, if they are taken from a body of water or aquarium unfavorable for this disease. All diseases that are classified as contagious are found in natural bodies of water, and free-living fish suffer from them. The task of the aquarist, first of all, is to protect their aquarium from these diseases as much as possible. To do this, it is necessary to observe a number of preventive measures.
However, even by observing maximum caution, it is impossible to completely secure your aquarium and avoid the emergence of infectious diseases in it. Practically in any aquarium and in the body of any fish, pathogenic agents can be found. The only difference is that fish kept in good (optimal) conditions, receiving a varied and complete diet, get sick much less often than fish that are weakened, depressed by poor maintenance and feeding conditions, and the presence of aggressive neighbors.
Unfortunately, diagnosing a contagious disease and treatment are available in most cases only to specialists, ichthyopathologists, veterinarians, and sometimes experienced aquarists. Many contagious diseases can only be identified in laboratories by autopsy of sick fish and examination of their internal organs. Undertaking treatment without knowing the diagnosis or the name of the disease is simply pointless. True, only a small number of diseases can be accurately identified by external signs and then cured. But there are few such diseases. Therefore, disease prevention remains the main, and sometimes the only, condition for the health of your aquarium.
Before saying: “I want!”, think whether the fish “want” it.
Almost every beginner aquarist thinks about breeding right away. For some reason, “just keeping” and caring for fish suits very few people. And a “black” streak begins in the life of the fish. Especially those with full bellies. And for the aquarists themselves, this is also a time of great hassle and bitter disappointments. And the most curious thing is that from various sources, both literary and from the stories of amateur aquarists, it is known that breeding these fish is not so difficult at all. It is indeed not difficult, but…
When you hear a question about how to “achieve” offspring from a particular species, you immediately think that this amateur is unlikely to succeed, at least until he gets tired of “achieving”. Especially in such a subtle and delicate process as breeding. You can strictly follow recommendations, prepare the water composition with great accuracy according to these recommendations, not forget about temperature and other details of the breeding technology, but achieve absolutely nothing comforting. When breeding fish, such punctuality does not always lead to the desired result.
Because it is in the fish themselves, their physical condition, health, their readiness and desire to participate in spawning at the moment, behavioral characteristics, rather than water hardness and pH, that the key to solving your failures is most often found. A beginner aquarist needs to develop observation skills, closely look at their pets, replenish their knowledge about them, learn not only to understand, but also to feel their simple desires, their mood and well-being, and give up much for the sake of one thing — creating favorable conditions for their pets.
Only from healthy, well-developed, sexually mature fish not depressed by poor maintenance and feeding conditions can you expect offspring. Therefore, if you have enough patience, the time will come and you will see a male releasing bubbles while building a nest, Pterophyllum conscientiously cleaning a wide plant leaf, preparing it for spawning, and much more will be seen by someone who will not scatter, will not rush events, and will learn to push the fulfillment of their personal desires to the background, striving, above all, to know, guess, and if possible satisfy the “desires” of their pets. And this is the shortest and perhaps the only path to the joy of first success.
For people seriously engaged in breeding exotic fish at home, the issue of rational use of existing aquariums occupies far from the last place. This can be a long aquarium divided into sections by partitions. It is easiest to make partitions from plexiglass 1-3 cm below the edge of the aquarium itself, to avoid accidental overflow of water over the edge. The number of holes in the partitions should be sufficient for the free flow of water, and their size should prevent fish and fry from penetrating into neighboring compartments. In the end section, there is a heater with a thermal relay and a filter pump with a hose of a suitable diameter put on the outlet pipe.
The hose is passed along the entire aquarium through holes in the bridges. Thus, water is discharged in the opposite part of the aquarium. It flows back by gravity according to the principle of communicating vessels through the holes. An aquarium for raising fry is best equipped with a much softer airlift circulation, otherwise the lion’s share of dust-like food will quickly end up in the filter. A sectional aquarium is convenient because it eliminates the need to use multiple filters and heaters required when servicing separate containers.
Slovenliness is an enemy of the aquarium. The theory of “old water”. 
