Why the guppy the most popular tropical fish? Many reasons could be advanced explaining the guppy's popularity in terms of its hardiness, beauty, availability, interesting habits and capacity for improvement through genetic experimentation.
The original wild guppy was a pleasing fish, but it was removed from today's brilliantly colored, long-finned specimens. Still and all, it carried within itself the seeds of its current favor, for the present fancy guppy and its forerunner are scientifically identical. Ichthyologists make no distinction between the prize-winning veiltail and the lowliest reject; both are the same fish, Poecilia reticulata and both require the same treatment if they are to be kept successfully. The fancy "hybrid" strains of today are not really hybrids in the strict sense of the word, for they have not been produced through interspecific cross-mating. However, the term "hybrid" has come into popular usage as a means of giving a general classification to the vast body of currently popular varieties.
The present fancy guppies are fish whose beauty can hardly be matched. Long before the present strains of exotic guppies were developed, aquarists were improving, by careful selective breeding, the common wild guppy. because this development reached proportions beyond those expected, guppy fancier groups were established. There still remains an unlimited scope for any aquarist to develop a specialized strain. The key to the enthusiasm of aquarists for the guppy lies in the fact that, irrespective of the great care in selecting a breeding pair, the young from any given mating may vary greatly in their color patterns. Until a strain is fixed, only a small percentage of the fry grow up to resemble their parents exactly. However, these varying color patterns are the foundation upon which further development by experimentation can be undertaken.
Plants are an integral part of the good guppy tank, for they are both useful and decorative. They provide shelter, shade and food. Guppies may be maintained without having any plants in their tanks, but such tanks never look as pleasing as planted ones.
Many aquarists prefer to restrict the compost for their plants to small amounts in ceramic containers in which the plants are grown. However, it is advisable to consider having compost covering the entire bottom of the aquarium. Choice of plants to be used is more or less a matter of personal taste. Any of the Sagittaria or Vallisneria varieties are excellent.
However, many of the experts prefer to use only watersprite (Ceratopteris thalicroides). They are of the opinion that this plant assists greatly in maintaining the desired water conditions. The pH is not crucial as long as extremes are avoided. A suitable pH range is 6.6 to 7.6, but once the pH is established it should be maintained as constant as possible. The water hardness (carbonate hardness or the DH) should be around 4 to 6 degrees, which is not soft but it is not very hard either.
crystal-clear water is not the answer to success, especially when an endeavor is being made to develop one particular color pattern. If a small amount of peat moss is steeped in boiling water, a few drops per gallon of the resultant solution will give the water a slight amber tint. This is more natural water condition for guppies, and it seems to improve their general physical condition. Temperature control at a constant level is of some importance, but slight fluctuations that do not vary gradually more than 3 to 5 degrees cause no serious harm to the fish. Temperatures between 72 and 76 F are ideal.