Check two numbers before anything else: the water temperature and the temperature on the surface of the dock, both with a probe thermometer. Most basking problems are temperature problems, and most of them are fixed in an evening. If the turtle is basking all day and also has bubbles at the nose, swollen eyes, or floats tilted, skip the rest of this page and book a reptile vet.
Basking all day
A turtle climbs out to warm up. Once it is warm it goes back in to eat and swim. A turtle that stays out has a reason, and these are the common ones, in order.
- The water is cold. Below 75°F a slider will not want to be in it. VCA gives 75 to 82°F for the water; check that the heater is on, is big enough for the tank and is not stuck.
- It is sick. A turtle with a respiratory infection stays out because it breathes more easily dry and because warmth fights infection. Look for bubbles at the nose, open-mouth breathing, a stretched neck, closed eyes. Sick turtles also often stop eating.
- The water is foul. Turtles avoid water that stinks. If the tank smells, do a 50 percent change with conditioned water at tank temperature.
- She is carrying eggs. A female of 5 inches or more that is restless, digs at the dock and stops eating may be gravid, and females lay without a male. She needs a tub of damp sand or soil 8 inches deep to dig in. If nothing comes in two weeks, a vet can X-ray her.
- It is new. A turtle in a new tank often spends the first week or two out of the water. Leave it alone and it will settle.
Never basking
- The dock is too cold. The surface should read 90 to 95°F. Veterinary care sheets range from about 85°F (VCA gives 75 to 88°F for the basking area) up to 95°F; anywhere in the upper part of that range works, and below 80°F does not. A 75 W bulb at 8 to 12 inches usually gets there. Move it closer or go up a size.
- The dock is too hot. Above 100°F the turtle will climb out, feel the heat and go straight back in. Raise the lamp.
- The water is too warm. At 85°F there is no reason to leave it, and warm water breeds bacteria. Turn the heater down.
- It does not feel safe. A tank in a busy hallway, next to a television or at child height means the turtle only basks when nobody is there. Check the shell first thing in the morning: a dry shell means it is basking at night or at dawn and you are simply missing it. If so, there is no problem to fix.
- It cannot get up. A ramp steeper than about 30 degrees, or a slick one, defeats a young turtle. Add a textured ramp or a rock step.
- The lights are off too long. Twelve hours of lamp and UVB a day, on a timer.
Why it matters
A turtle that never dries off cannot use its UVB lamp, because the UVB has to reach the shell, and without it the shell softens over a year or two. The shell also never dries, and a wet shell under lifting scutes is where shell rot starts. A turtle that never warms up cannot digest properly and eats less. A turtle that basks all day is not eating either. Either way the problem compounds over weeks, which is why it is worth an evening with a thermometer.
The quick table
| What you see | Likely cause | Fix |
|---|---|---|
| Out all day, water under 75°F | Cold water | Heater to 75 to 80°F |
| Out all day, bubbles or gaping | Respiratory infection | Vet this week |
| Out all day, digging, not eating | Gravid female | Nesting tub, then vet |
| Never out, dock under 85°F | Cold dock | Lower or upsize the bulb |
| Never out, dock over 100°F | Hot dock | Raise the lamp |
| Never out, dry shell at dawn | Shy turtle | Nothing, it basks at night |
When a vet is needed
Basking all day with any breathing sign, swollen eyes, or a refusal to eat for a week. Never basking with a shell that gives under your thumb. Floating tilted at any time. The vet will check temperatures with you, examine the eyes and nose, X-ray the lungs or the abdomen, and treat with antibiotics or vitamin A. A gravid female who cannot lay may need an injection to bring the eggs on, or surgery.
What to buy
A digital probe thermometer, and buy two: one taped to the dock, one in the water. A 75 W basking bulb if the dock reads cold. A 300 W submersible heater with guard if the water does. An outlet timer gives the turtle a day and a night. The vet directory lists reptile vets by state.
Sources
- Housing for Aquatic Turtles, VCA Animal Hospitals
- Common Diseases of Aquatic Turtles, VCA Animal Hospitals
- Disorders and Diseases of Reptiles, Merck Veterinary Manual
Written from these and checked three times before publishing. Not veterinary advice; a reptile vet who can see the animal beats any page.
