| The hobby of aquarium keeping and tropic fish as | | | | development of the plants... |
| pets is fairly recent in the Western World, and took | | | | Larger tanks are very attractive and give scope for |
| a while to catch on. The keeping of fish in small | | | | beautiful planting arrangements and for fine growth |
| indoor tanks was only seriously considered in the | | | | of the fishes, but they are expensive and not likely |
| middle of the last century, when both in Britain and | | | | to become generally popular. Most fish lovers |
| the rest of Europe a considerable interest in the | | | | therefore prefer a range of medium tanks rather |
| subject developed... | | | | than one or two very large ones, but it must be |
| At the beginning of the 1900's aquarists around the | | | | emphasized that fine fishes can be grown in large |
| world began to keep tropical fishes, and it was the | | | | tanks... |
| "trend" of so doing that started a new wave of | | | | In general, tropical fishes can be housed in smaller |
| popular fish culture (keeping fish as pets)... | | | | tanks than cold-water fishes. This is because they |
| The older aquarists were obsessed with copying | | | | are usually smaller and are also better able to |
| nature in their tanks--or rather with the attempt to | | | | withstand a relative deficiency of oxygen in the |
| try and copy nature--whereas the keepers of | | | | water... |
| warm-water fishes had to experiment and create | | | | Size for size, most tropical fishes can be crowded a |
| suitable environments for them... | | | | good deal more than the common goldfish and very |
| Often they started only with the knowledge that the | | | | much more than fancy varieties of goldfish. A |
| fish must be kept warm, and this in itself raised | | | | 15-gallon tank might comfortably contain a dozen |
| problems, including the death of favorite weeds and | | | | 3-inch rosy barbs, four or five 3-inch common goldfish |
| water snails at higher temperatures... | | | | at the most, and not more than a pair of Orandas of |
| So the aquarium gradually came to be regarded as | | | | the same size... |
| most of us see it today, as a beautiful display, not a | | | | Fish consume solid food and excrete solid faeces. |
| mirror held up to nature... | | | | They breathe oxygen and exhale carbon dioxide, and |
| However, until the keeping of tropical fish, it seems | | | | therefore they tend to deplete their environment of |
| that aquarists in general thought that the proper aim | | | | oxygen and to pollute it with carbon dioxide and |
| of an aquarium keeper was to reproduce a segment | | | | excrement... |
| of nature... | | | | Plants also breathe oxygen, but in sufficiently bright |
| They now realize that their task is the maintenance | | | | light they manufacture sugars, etc., from carbon |
| of a highly artificial and restricted community of | | | | dioxide taken from their surroundings, whether air or |
| animals and plants, with a balance that can easily | | | | water, and they release oxygen. This is done in the |
| topple with disastrous results to at least some of the | | | | green leaf... |
| members. At the same time, aquariums can generally | | | | Plants also absorb dissolved salts and use these |
| be easily maintained as long as a few fundamental | | | | together with carbon dioxide in building up complex |
| facts are recognized and applied with commonsense | | | | organic compounds. Very few higher plants can utilize |
| to the problems that arise... | | | | solid or very complex substances, and before animal |
| So lets talk now about some of the characteristics | | | | excrement (usually known as "mulm" in the fish tank) |
| of aquariums and tropical fish... | | | | is available to them it must be broken down by fungi |
| The old fashioned fish bowl has almost completely | | | | or bacteria and made soluble... |
| replaced for serious fish-keeping by the rectangular | | | | So plants, in adequate light, tend to restore oxygen |
| glass tank, either made wholly of glass or with a | | | | to the environment and to remove the waste |
| metal frame and glass sides and a bottom of glass, | | | | products of animals. In poor light or in darkness they |
| slate, or other rigid material... | | | | deplete the water or air of oxygen just as animals |
| Except when used for spawning, for exhibition | | | | do. It is only in the daytime, or under bright artificial |
| purposes, or as a hospital tank for the treatment of | | | | light, that they perform the complementary function |
| disease, the tank contains growing, rooted plants; | | | | to animals... |
| these are set in a sand or gravel layer 1 or 2 inches | | | | From these facts grew the concept of a balanced |
| thick. There may be decorative rocks, but the chief | | | | aquarium, with the waste products of the fishes |
| decoration is usually the plants themselves, which | | | | absorbed by the plants, and the oxygen necessary |
| contribute more to the attractive appearance of a | | | | for the fishes provided by the action of the plants in |
| well set-up tank than do the fishes... | | | | light... |
| Rectangular tanks are usually between 5 and 25 | | | | The moral of the story? A well-planted tank with |
| gallons in capacity; a 15-gallon tank measures 24 X 12 | | | | adequate illumination will usually stay clear and sweet |
| X 12 inches and is a favorite size. Smaller tanks than | | | | for months or years with little attention... |
| these cannot house many fish or allow proper | | | | |