Using Thermometers in Your Aquarium

By encasing the heater and thermostat in separate tubes, one is enabled to place the heater in one corner and the thermostat in another. This is supposed to insure a more even distribution of heat, since the heat must travel through the entire tank to reach the thermostat. In theory it is all right, but in actual practice it has hardly proven necessary. Water circulation itself distributes the heat readily enough.

Any type of thermometer can be used in a fish tank that is partitioned into several sections. Judge the wattage required by the capacity of the tank. Place the thermostat and heater in the center section or in adjoining sections. The end sections may be a few degrees cooler than the center, but the difference will not be appreciable.

To make sure that your thermometer is giving the correct reading, place your thermometer alternately in warm and cold water to see if it rises and falls properly. Wash the thermometer carefully, and place the bulb edge under your tongue. An accurate thermometer will read close to 98.6° F., which is body temperature. A variance of 2° or 3° is not important, however, since aquarium temperatures are not that critical.

Check a new thermometer for breaks or spaces in the mercury or “spirit” column. These often occur because of jostling during transit. To eliminate such breaks, place the thermometer on a piece of ice until the indicator has retracted completely into the bulb. When the indicator fluid is allowed to warm up, the column should be continuous.

What is the best way to light an aquarium?

The aquarium should be lighted from the front and the top. The rays of the light should be directed down and back toward the rear, bottom. They should be directed away from the viewer’s eyes, striking the fishes directly to reveal their beauty. Light coming from the rear tends to silhouette the fish and to conceal refractive colors.

As a general rule, eight to ten hours of light a day, utilizing the wattages given, will result in satisfactory plant growth. Larger wattages may be used for lesser periods of time, and smaller wattages for greater. That there is a point of diminishing returns is obvious. Too low a wattage will not penetrate a depth of water; too high a wattage may overheat the upper layer of the water. Observation over a period of time will determine the most satisfactory wattage to use and the proper period of time to keep the lights on.

The most satisfactory arrangement is one that keeps the plants healthy and the algae growth down to a minimum. Should the plants start to deteriorate, usually more light is required; that is, higher wattages or a longer period of illumination.

Excessive growth of algae usually indicates too much light and, possibly, an excess of decomposing organic matter. The remedy, usually, is to decrease the amount of illumination and to siphon off all excess food and foreign matter. A certain amount of algae is bound to form even under ideal conditions. But you can keep this minimal growth in check by scraping and by using scavengers. You should be most concerned with the wild, seemingly uncontrollable growth that coats the rocks and plants and turns the water green.

Certain colors, although pretty to see, actually inhibit the growth of plants. The warmer tones at the red end of the spectrum are the most satisfactory for plant stimulation. Blue colors are the least helpful. The most practical are the uncoated clear glass bulbs which have a long filament. Although there are a number of inexpensive bulbs on the market which have short filaments, actual tests have proven them to be less effective than the long in stimulating plant growth. Any coating on a bulb must of necessity diminish the amount of light reaching the plants and thus decrease the effectiveness of the bulb.

Heating Your Aquarium

Because aquarium fishes are usually referred to as “tropical” fishes, the idea has become erroneously established that they require high temperatures for survival. The truth is that 75° F. is warm enough for tropical fishes, with rare exceptions. In fact many of our aquarium inhabitants are only semi-tropical; and will thrive in even lower temperatures.

Your main concern should be with temperature extremes and temperature fluctuations. Too extreme a fluctuation, even within the favorable range, can lead to difficulty. Fluctuation even within the fishes’ range is the problem that is usually the most difficult to solve. For example most tropical fish are comfortable within a low of 70° F. and a high of 85″ F.; 75° F. is considered ideal. But suppose that the tank’s position is near a radiator, or in a sunlit area, or that the wattage of the reflector bulbs is too high. Any one of these could cause the temperature to rise to 85″ F. during the daytime. These sources of heat are not present during the night and the tank’s temperature may drop to 70° F. This gives a fluctuation of 15° F. in twenty-four I hours. Fishes continually forced to adjust themselves to such temperature changes are under a definite strain; they become weakened and subject to disease.

Considering the abuses to which they are frequently subjected by well-meaning fanciers, they are remarkably hardy. I have seen fishes subjected to such extreme cold hat they floated torpid and, to all appearances, lifeless at the surface. When warmed up - and in these cases If was a fairly rapid warming - they recovered promptly and vigorously. Moreover, fishes seem to be capable of swimming without difficulty through strata of water at different temperatures. A reflector might raise the water’s surface temperature 5° or 6° higher than the bottom temperature, yet the fishes swim up and down with no sign of discomfort.

There is a school of thought which holds that it is necessary for the temperature to fluctuate a few degrees between day and night in order to more closely duplicate f he fishes’ natural environment. This hardly seems necessary. Inhabitants of aquariums with controlled temperature fluctuation appear to be in no better condition than I hose in aquariums maintained at a constant temperature.