Red-Eared Slider Turtle Care Guide

The red-eared slider (Trachemys scripta elegans) is a semi-aquatic turtle from the southern United States that is sold palm-sized but grows to dinner-plate size and can live for decades. It suits an adult prepared to run a large, filtered, heated tank for 30 years or more, not a household with children under 5. VCA uses the slider as its model for pet aquatic turtles generally, so the setup below is also the starting point for painted turtles, map turtles and cooters, with species-specific temperatures and diet.

Care requirements

Need	What to provide
Enclosure	About 10 gal of water per inch of shell (roughly 15 L per cm), deep enough to swim submerged, plus a dry basking area covering 15–25% of the surface (VCA; RSPCA)
Temperature	Water 75–82°F (24–29°C), never below 65–70°F (18–21°C) at night. Basking spot: VCA gives 75–88°F (24–31°C), the RSPCA 86–95°F (30–35°C). Use a thermostat (VCA; RSPCA)
Lighting	7–12% UVB tube over two-thirds of the tank, with nothing between lamp and turtle, on a 12-hour timer. Replace about every 6 months (RSPCA; VCA)
Diet	Omnivore: commercial turtle pellets, thawed freshwater fish, safe plants such as pondweed, and invertebrates, with calcium. Feed every two days, as much as it eats in 5 minutes (VCA; RSPCA)
Lifespan	Around 30–40 years in captivity (RSPCA)
Social needs	Fine alone. If you keep more than one, give each a basking spot, match their sizes and watch for bullying (VCA; RSPCA)
Legal notes	US: no sales under 4 in (10 cm) shell since 1975. UK: no sale or breeding. EU: on the invasive species list, with sale and keeping restricted (CDC; RSPCA; European Commission)

Sizing the tank for the adult, not the hatchling

Hatchlings grow fast. Adult females average 10–12 in (25–31 cm) of shell and males 7–9 in (18–23 cm), according to VCA. By VCA’s 10-gallons-per-inch guide, a 10 in female needs about 100 gal (380 L) of water. The RSPCA’s figure works out much the same: 80 litres per 5 cm of shell, so 400 L for a 25 cm shell. Both organisations say it is cheaper to buy the adult-size tank first and raise the water level as the turtle grows.

The dry platform should sit under the heat lamp at one end so the turtle can climb fully out and warm its whole body, with a ramp up from the water. Add a second, cooler resting spot elsewhere. Guard all heat and UV lamps so the turtle cannot touch them, and use a mesh lid rather than glass, because good ventilation reduces health problems (RSPCA).

Water quality is most of the work

Sliders eat and defecate in the same water and produce a lot of waste. VCA calls a filter or weekly water changes “critical”, and lists poor water quality and diet among the main reasons sliders do badly. Use a powerful external filter. The RSPCA’s routine is:

• a 20% water change each week with dechlorinated water
• rinsing filter sponges in tank water so you keep the beneficial bacteria
• test kits for ammonia and nitrite. If either is high, change half the water daily until it falls.

Feeding in a separate container keeps food debris out of the main tank (VCA). Overfeeding is the biggest cause of dirty water, and it also causes obesity and growth that is too fast (RSPCA). Warm new water to tank temperature before the turtle goes back in, because sudden temperature drops affect immunity and digestion (VCA).

UVB, calcium and shell health

Without UVB, a slider cannot make vitamin D3 or absorb calcium. It then draws calcium from its own bones and develops metabolic bone disease. VCA notes this is fatal if left untreated. Early signs are swelling around the mouth or eyes, an uneven shell, or a soft, rubbery shell in young turtles (RSPCA). UVB does not pass through glass or plastic. Mount the lamp 12–18 in (30–45 cm) from the turtle (VCA), and if you can, use a UV index meter to aim for UVI 3–5 at the basking spot (RSPCA). Offer cuttlefish bone as a calcium source. Include beta-carotene vegetables such as sweet potato to protect against vitamin A deficiency, which shows up as swollen or sunken eyes (RSPCA; VCA).

Salmonella and release: the public-health side

The CDC says reptiles commonly carry Salmonella in their gut even when they look healthy. Children under 5, adults over 65 and people with weakened immune systems are most at risk. The US banned sales of turtles under 4 in in 1975 because small turtles pose a higher disease risk to children, who may put them in their mouths (CDC; VCA). The CDC credits the ban with preventing an estimated 100,000 child infections a year, though small turtles are still sold illegally at souvenir shops and roadside stands. Wash your hands after touching the turtle, its food or its water. Keep the turtle and its equipment out of the kitchen and anywhere food is prepared or eaten (CDC).

Never release a slider. The European Commission records over 50 million sliders imported into Europe for the pet trade. They are now established in at least 22 EU member states, where they compete with native pond turtles for basking and nesting sites. In the UK it is illegal to sell or breed them, and they must be kept securely (RSPCA). If you can no longer keep one, contact a reptile rescue.

Gotchas

• Buying a hatchling for a child. The turtle will outgrow a starter kit within months and outlive the child’s interest by decades. Young children are also the group most likely to get seriously ill from Salmonella (CDC).
• Gravel in the tank. Sliders swallow small stones, which can cause gut inflammation or a blockage (VCA). Use fine sand in a thin layer or no substrate, or stones too big to swallow (RSPCA).
• UVB lamp behind a glass lid. The turtle gets no UVB at all, and metabolic bone disease follows (VCA).
• Letting it hibernate. Hibernation suppresses a pet turtle’s immune system. Keep temperature and light steady all year (VCA).
• Feeding live fish or frozen fish that isn’t fully thawed. Live fish are chased and stressed. Fish that is still partly frozen can make the turtle very ill (RSPCA).

Avoid

• Small gravel or pebbles the turtle could swallow
• Heat lamps or water heaters without a guard and a thermostat
• Plastic plants, which a turtle may eat, and any real plant you can’t confirm is safe
• Glass or plastic between the UVB lamp and the turtle
• Live feeder fish as tankmates
• Overdosing vitamin D3 supplements when the UVB setup is already correct (RSPCA)
• Cleaning tank equipment in the kitchen or anywhere food is prepared (CDC)

Signs to see a vet

See a reptile vet if you notice sunken or swollen-shut eyes, discharge from the nose or eyes, or red spots or pinpoint bleeding inside the mouth (possible mouth rot). Other red flags are a soft, pitted or discoloured shell, a turtle that floats lopsided in water, constant shedding or sores, or a turtle that stops eating (VCA; RSPCA).