Читать книгу Harper's Outdoor Book for Boys - Joseph H. Adams - Страница 11

It is generally supposed that it is necessary to change the water in an aquarium at least once a day; but that is not the case. The true principle on which an aquarium should be conducted is not to change the water at all, but so to aërate and refresh the original supply as to maintain it always in a pure and perfect state. There are several means by which this may be done. The healthy growth of plants is very important, and active and brisk contact with the air of the atmosphere will greatly freshen the water. Motion in the water is absolutely necessary. In large aquaria this is obtained by an arrangement of tanks into which the water is pumped, and from which it flows rapidly, circulating through the tanks where the fish live. In its passage through the air it absorbs considerable oxygen, without which no fish can live. Fish placed in water that has been boiled die in a very few minutes.

The first thing to be done in the formation of a fresh-water aquarium is to start your plants in proper soil at the bottom of your tank, fill the tank with water, and leave it undisturbed until the plants begin to grow and the little bubbles of oxygen are to be seen rising to the surface of the water.

Choose your plants from such as you may collect from rivers or brooks or ponds anywhere in the country. Plant them, and then cover the surface of the soil with pebbles and small bits of rock, or anything that is suitable and in keeping with the rest of your arrangements. Never put sea-shells into a fresh-water aquarium.

Now fill your tank with water poured through a siphon or funnel, being very careful not to disturb the soil or the roots of the plants. You should have some clean river-sand in the bottom of your tank, and your pieces of rock should be so arranged as to form little caves and hiding-places for your fish. It will take perhaps two weeks to get your tank into a proper condition for fish to live in. Every bit of dead or decaying vegetation should be carefully removed. Keep your tank shaded from the heat of the sun, and expose it to the bright light only once in a while.

In order to manage your aquarium properly you will require a few simple tools. A little hand-net that can be bought for a few cents, or made for even less out of a bit of wire and a small piece of mosquito-netting, is useful for catching the fish or shells without putting your hands into the water. A pair of wooden forceps, like a glove-stretcher, will be found most convenient for nipping off bits of decaying plants or for catching objects that may have accidentally fallen into the water. Glass tubes of various sizes are also useful. If you want to catch any small object in the water with the tube, place the tube in the water with your finger over the hole in the top. Until your finger is removed the tube will remain full of air. Place it over the bit of refuse or whatever it is you want to catch, remove your finger, and the water will rush in, carrying the object with it into the tube, which should then be closed at the upper end by placing your finger over it as before. A glass or hard-rubber syringe is necessary with which to aërate the water thoroughly at least once a day, and oftener if possible. Fill the syringe, hold it high above the tank, and then squirt the water back again.

If a green film begins to gather on the side of the tank that is most exposed to the light, it should be cleaned away every day, and the sides of the glass polished carefully. A small piece of clean sponge tied on the end of a stick will answer the purpose very well, and, if used daily, you can keep the glass clear with very little trouble; but if the scum is neglected and left to accumulate, you will find it almost impossible to remove it from the glass even by hard scouring.

It is best to have only small fish in your aquarium, and for this reason trout are not desirable. Although very beautiful and intelligent, they grow so rapidly that they are likely to become in a short time too unwieldy for your tank. Goldfish and minnows are very good, and the common little sunfish or “pumpkin-seed” is excellent.

You must keep careful watch over the fish in your aquarium, and if any one of them appears to be sick he should be removed at once, very gently, with the hand-net, and placed in fresh water, where he will often recover. If, however, the little sufferer is doomed to die, it is better not to run the risk of his doing so among his healthy companions. It is best always to have a hospital for your sickly pets, and as soon as one of them, whether a fish or a bird or any animal, shows signs of ill health, he should be taken away from the others and placed by himself.

Certain varieties of snails live well in fresh water, and will be found useful in clearing away the green film that is almost certain to collect on the side of the glass; but you must be careful or they will devour your plants as well; and if your tank is very small it is hardly worth while to try to keep them.

Water-beetles and water-spiders also thrive well, and their habits are most interesting to watch; but water-beetles fly by night, and unless you are careful to cover your tank you are likely to discover some morning that a number of your tenants have taken French leave.

You must be careful not to overstock your aquarium, for your fish will not thrive if they are overcrowded. Remember, also, that heat and dust are fatal to your pets. The water must be kept clean and cool at all times, and all foreign matter and every particle of decaying vegetation should be removed immediately.

To manage an aquarium successfully, no matter on how small a scale, requires a good deal of care and time, but you will find it time well spent, and the pleasure and knowledge the study of your pets will give you will be an ample return for the time you spend on them.