Housing: The type and size of enclosure used depend upon the species, number and size of the water turtles to be housed. Hatchlings can be kept indoors in small aquariums. Older or larger specimens require a large aquarium or an outdoor pond (cement or plastic-lined). Contact the organizations and associations listed at the end of this pamphlet for further information on pond construction. Careful attention must be paid to filtration systems, cleaning requirements, and ease of draining water from ponds used to house water turtles. Rigid molded plastic swimming pools for children are also suitable for housing water turtles, provided they are adequately equipped with a filtration system and means to replenish the water. Any enclosure should provide adequate room for swimming and sufficient dry area for resting and sunning. Providing a dry, nonsubmerged area is very important. Water turtles, especially juveniles, can become exhausted and drown when no such dry area is provided. Very small water turtles can be provided with a piece of partially submerged wood or cork bark onto which they can crawl for basking or under which they can hide. Larger and heavier water turtles require a more solid and immovable basking area on which to completely crawl out of the water and rest.
A platform of flat rocks or bricks can be fashioned or a ribbed wooden platform, the surface of which rests just above the water's surface, can be provided or basking. Any wooden platform must have a substantially weighted base so it does not topple over. Driftwood, provided it is well anchored, can also be used for resting and basking, and is a visually appealing addition to an enclosure. If an aquarium is used to house a water turtle, one end can be used for a basking area. A pane of glass an be inserted into the aquarium to divide it About two-thirds of the available area can be allocated for swimming and about one-third of the area for basking. Gravel can be used to fill the basking side. Green plants can also be planted or placed in this area desired. A small ramp made of wood or plastic can e attached to the dividing pane of glass to allow the turtle easy access to the basking area. This area is also advantageous for breeding female turtles because it gives them a suitable area for laying their eggs. The bottom covering for the enclosure must be carefully selected for the species being housed, and must be non-toxic and non-abrasive. Soft-shelled turtles (family Trionychidae) like to burrow and require very fine sand at a depth that allows near total covering of the upper shell. Small rocks should never be used because they can be swallowed, resulting in damage or impaction to the intestinal tract.
Water Hygiene and Sanitation: The water level provided should be at least as deep as the turtle is long, preferably several times this measure. Tap water is acceptable provided it is allowed to stand undisturbed for at least 48 hours before the turtle is introduced. This is necessary for the water to become free of chlorine and chloramines. Water treatment systems sold at pet shops that are recommended for tropical fish may also be used to remove these chemicals from city water. Sometimes unfavorable local conditions can make tap water unusable. The high iron content or fluoridation procedures of certain water supplies can be harmful to water turtles. Bottled water is probably safest for delicate water turtles and for species whose actual aquatic requirements are unknown. Brackish water can be approximated for species that require it (such as the Diamondback Terrapin) by adding 1 tbsp of uniodized salt to each gallon of water. In the wild, the relatively large bodies of water in which turtles live tend to reduce the concentration of waste products and uneaten food. Consequently, free-living water turtles are rarely affected by the decomposition and bacterial proliferation that inevitably follow. This is not the case with captive water turtles. Because of the relatively small water volumes of aquariums and ponds, these limited enclosures tend to concentrate waste material. This represents a potential hazard for the turtles because disease causing microorganisms that feed on this material also multiply. Turtles, therefore, live in a "soup" of potentially harmful microbes and disease is an ever-present threat if sanitation is poor.
Every effort should be made to prevent soiling of the environment. All fecal matter should be netted or siphoned away as soon as possible. Water turtles should be fed in an environment separate from their living environment to reduce contamination of the water. A small aquarium, hard plastic dishpan, or even a bucket works well in this capacity. A filtration system is necessary to maintain optimum water quality. Undergravel filters work best, except when soft-shelled turtles are housed in an enclosure. This type of turtle tends to continually stir up the bottom material. Outside filters are efficient, provide high flow rates, and are relatively easy to clean. The comer filters routinely used with tropical fish are not as effective or useful when used with water turtles. Adding small amounts of vinegar to maintain a water pH of 6.0-6.5 (slightly acidic) may help keep bacterial counts low. One teaspoonful of non-iodized (aquarium or rock) salt added per gallon of aquarium water may also help in this capacity. At least once monthly, the water turtle's enclosure should be entirely dismantled (including the filtration system) and thoroughly cleaned. It is not practical to maintain this cleaning schedule with ponds and other large enclosures. These should be cleaned at least every 36 months.
Temperature: Hobbyists should attempt to duplicate the air and water temperatures experienced by water turtles in their natural environment When temperatures drop, turtles become sluggish and stop eating. Food already within the digestive tract may ferment or putrefy, allowing bacteria to multiply and perhaps cause disease. Many species tolerate room temperatures for both air and water. When in doubt, provide the range of temperatures used for tropical fish (70-80 F). Water turtles that originate from tropical climates require a heat source. Aquarium heaters work best for indoor aquariums. Large tanks and outdoor ponds require a specially designed water heater that maintains a constant temperature. An incandescent light bulb or heat lamp can be installed directly above the basking area to provide supplemental heat Most experts believe turtles remain healthier if they are permitted to seek out heat when they desire it Great care should be taken to ensure the temperature at the level of the basking surface does not exceed 90 F. Such heat sources may also increase the water temperature in very small aquariums to undesirable levels. A thermometer should be placed in the water and another on or near the basking surface so the temperature of these areas can be continually monitored.
Light: Ultraviolet (UV) light helps maintain health because most light bulbs do notemit UV light. Also, the UV light is filtered from sunlight as it passes through window glass or plastic. Consequently, none of these sources is suitable for captive reptiles, including water turtles. If artificial UV light sources are unavailable, captive water turtles should be exposed to direct sunlight for 24 hours daily. Most turtles take advantage of the warm sunlight by resting on their basking areas. The water in very small aquariums can readily become overheated if this sunlight exposure schedule is rigidly followed. Therefore, caution should be exercised. An alternative to direct sunlight is an artificial UV light source, such as a Vitalite (Dura-Lite Lamps, Duro-Test Corp, Lyndhurst, NJ 07071), that can be used during daylight hours. Such a light source should be left on during daylight hours to approximate a natural photoperiod. It is best to supply 10-12 hours of daylight and 12-14 hours of darkness each day, with a gradual increase in the number of hours of light supplied in the spring and a gradual decrease in light provided in the fall and winter months.