Reptiles · Turtles
Red-eared Slider
Trachemys scripta elegans
Common aquatic turtle needing a large tankAdvanced
- Lifespan
- 20-30+ years
- Size
- 15-30 cm (females largest)
- Social needs
- Can live singly; not dependent on company
- Time
- Medium-High; daily feed, heavy filtration
- Cost
- High
- Diet
- Omnivore (pellets, greens, some protein)
Overview
What is this animal?
- The red-eared slider is one of the most widely kept aquatic turtles, recognised by the red stripe behind each eye.
- Cheap hatchlings are sold in tiny bowls, but they grow into large, messy, long-lived turtles that need a substantial aquatic setup and decades of care.
- Underestimating their size, mess and lifespan leads to many being released, where they become a damaging invasive species in many countries; in some places sale or release is now restricted.
- Acquire one only with the space, filtration budget and 20-to-30-year-plus commitment they genuinely require.
Temperament
- Red-eared sliders are active, alert, strong swimmers that quickly learn to beg at feeding time, which many owners enjoy.
- They are not affectionate and generally dislike handling, which can stress them, and larger turtles can deliver a painful bite if mishandled.
- They do not need company and are often best kept singly, as multiple turtles increase waste, competition and aggression, and adult males may harass tank-mates.
- If kept together, they need much more space and careful monitoring.
- For most keepers, one well-housed turtle is the simplest and kindest choice.
A good fit for
- Keepers with room for a large aquatic setup
- People who enjoy watching rather than handling
- Owners ready for heavy filtration and water changes
- Those committed to 20-30+ years of care
Common mistakes to avoid
- Tiny tanks and bowls for a growing turtle
- Weak filtration causing chronic poor water quality
- Never releasing one outdoors (invasive)
- Missing UVB and basking heat
Enclosure
Minimum 280 litres (74 US gallons)
Fine alone or with company. Can live singly; not dependent on company
- An adult needs an aquarium or pond of at least 280 litres (75 gallons) for one turtle, with several times its shell length in swimming depth, plus a dry basking platform.
- The basking area should reach 31-35C under a heat lamp, with water held around 24-26C by a submersible heater; keep juveniles and sick turtles warmer.
- They produce heavy waste, so a powerful external or canister filter rated well above the tank volume is essential, along with regular water changes.
- A UVB lamp over the basking dock is required for shell and bone health.
- Keep the basking zone genuinely dry so the turtle can fully warm and dry off.
Supplies
Setup
- Enclosure
- Heating and thermostat
- UVB fixture and bulb
- Thermometers and hygrometer
- Substrate and decor
Ongoing
- Quality aquatic turtle pellets (carnivorous formula for musk turtles)
- Frozen or live earthworms, shrimp and snails
- Leafy aquatic greens or romaine for the omnivores
- Floating cuttlebone
- Separate feeding tub
- Fine net for removing uneaten food
- Feeding tongs
- Kitchen scale for tracking growth
Safe substrate: Topsoil and play sand mix · Coco fibre and coir · Cypress mulch
Care routine
Daily
- Check humidity and damp the substrate
- Check temperatures and humidity
- Fresh water bowl
- Look the animal over
- Spot-clean waste and uneaten food
Weekly
- Feed to the species' scheduleevery 2 days
- Check the basking dock
- Hand-washing and food-area check
- Test the water
- Water change and debris vacuum
Monthly
- Weigh-inevery 2 weeks
- Deep-clean the enclosure
- Rinse the filter media
- Test thermostats, lamps and guards
Less often
- Refresh the substrateevery 3 months
- Replace the UVB lampevery 6 months
Vet: Annual exam and faecal check — every 12 months
Top resources for more info
Independent creators and organisations we would send a friend to. We have no affiliation with any of them, and nothing here is sponsored. Links checked 2026-09-19.
YouTubers
Garden State TortoiseAquatic and box turtle housing, ponds and seasonal careReptiles and ResearchEvidence-led husbandry: enclosure size, UVB, thermal gradients, enrichmentClint's ReptilesWhich reptile suits you, with honest care and handling verdicts
Sites
Go deeper
Diet
- Red-eared sliders are omnivores whose diet shifts with age.
- Hatchlings and juveniles are more carnivorous, while adults eat increasingly plant matter.
- Feed a quality commercial aquatic turtle pellet as a base, plus leafy aquatic greens, and offer protein such as appropriately sized insects for younger turtles.
- Feed juveniles daily and adults every two to three days, removing uneaten food to protect water quality.
- Provide calcium via a cuttlebone.
- Over-feeding, especially fatty protein and processed treats, plus low-calcium or low-UVB conditions, drives obesity, fatty liver, shell deformity and metabolic bone disease.
Health
- A healthy slider has a hard, smooth shell, clear eyes, a strong swim and a good appetite.
- Common problems include shell rot and soft shell from poor water quality or insufficient UVB and calcium, respiratory infection (gaping, listing in the water, bubbling) from cold water, and swollen eyes linked to vitamin A deficiency.
- Poor water quality underlies most illness, so filtration and water changes are central to health.
- Sliders can carry Salmonella, so hand-washing and supervision around children matter.
- Any turtle floating abnormally, refusing food or labouring to breathe should see a reptile-capable exotics vet.
Is your enclosure big enough?
Minimum volume280 litres (74 US gallons)
CompanyFine alone or with company. Can live singly; not dependent on company
Is this urgent?
For aquatic turtles the water quality is half the medical history.
Go now
Swimming lopsided, or unable to submergeGo now. Usually respiratory, and a turtle that cannot dive cannot feed.
NowToday
Soft or pitted shell, or white patches that lift awayBook, and test the water. Shell rot follows poor water quality or a basking site that never fully dries the animal.
This weekPuffy or closed eyesBook today and check the water. Often vitamin A deficiency plus dirty water.
TodayA turtle needs a basking site that gets it fully dry and properly warm. Half the common problems trace back to a dock that does neither.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
Can a red-eared slider eat that?
Reptile diets split hard by species. An insectivore and a grazing tortoise share almost nothing, so check the species guide as well as this list.
The full list
Never (15)
AlcoholNo safe amount at any body weight on this site.
neverAvocadoPersin. Fatal to many reptiles.
neverCaffeineCoffee, tea and energy drinks. Cardiac and neurological toxicity at tiny doses for an animal this size.
neverChocolateTheobromine and caffeine. Small mammals and reptiles cannot clear either.
neverCitrusToo acidic, and it interferes with calcium absorption.
neverDog or cat foodProtein and vitamin D levels formulated for a mammal. In tortoises it causes irreversible kidney and shell damage.
neverFirefliesLucibufagins. A single firefly has killed adult lizards. This is the most dangerous item on any reptile list and it is the one keepers do not know about.
neverFish caught from the wildThiaminase and parasite risk for turtles and aquatic species.
neverGarlicSame allium toxicity as onion, and more concentrated by weight.
neverIceberg lettuceWater with no nutrition. It fills a reptile up in place of food that would have done something.
neverLeekAllium family. Same mechanism as onion and garlic.
neverOnionOrganosulphur compounds damage red blood cells. The whole allium family is out.
neverRhubarbOxalate load high enough to cause acute kidney injury.
neverSalty or seasoned human foodSalt, oil and seasoning. Crisps, chips, seasoned leftovers and processed meat are all out.
neverWild-caught insectsPesticide residue and parasites, and the identification risk. Captive-bred feeders only.
neverRare treats (1)
WaxwormsVery fatty. Useful for a underweight animal or for medicating, addictive otherwise. One or two, rarely.
rare treatOccasional (5)
Bell pepperSafe, low oxalate, and the colour gets a refuser eating. A few small pieces a few times a week.
occasionalButternut squashWell tolerated and a useful source of vitamin A precursors. Small cubes a few times a week.
occasionalKaleGood calcium, mild goitrogen. Rotate it. Twice a week.
occasionalMealwormsHard chitin shell and a poor calcium ratio. Fine as part of a varied feed, poor as the whole diet. A few, alongside better feeders.
occasionalSpinachOxalates bind dietary calcium, which is the last thing a reptile at risk of metabolic bone disease needs. A very small amount, rarely.
occasionalEveryday foods (6)
Black soldier fly larvaeUnusually high in calcium; one of the few feeders that does not need dusting. Several per feed.
everyday foodCollard greensOne of the best staple greens for herbivorous and omnivorous reptiles. Daily.
everyday foodCricketsA standard feeder. Gut-load them for 24 hours before offering, or you are feeding an empty shell. Sized no wider than the space between the animal's eyes.
everyday foodDandelion greensExcellent calcium-to-phosphorus ratio and readily taken. Pick away from sprayed ground. Daily, for herbivorous species.
everyday foodDubia roachesBetter calcium ratio and more meat per insect than crickets, and they cannot climb glass. Sized to the animal.
everyday foodMustard greensGood calcium ratio; rotate with other greens. Several times a week.
everyday foodThat food is not on our list. Reptile diets are narrower than they look — check the species guide, and ask an exotics vet before offering anything unfamiliar.
Dust feeders with a calcium supplement to the schedule in the species guide. A reptile can be eating well and still be starving of calcium.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
Bedding and substrate
Substrate choice follows the animal's natural humidity, not the look of the vivarium. Get that pairing right and most substrate arguments disappear.
Safe
Topsoil and play sand mixThe standard bioactive-ready base for arid and semi-arid species. Plain topsoil with no fertiliser, no perlite, no wetting agents.
safeCoco fibre and coirHolds humidity well for tropical species. Rinse and check it is not bone dry, which makes it dusty.
safeCypress mulchGood humidity retention for tropical snakes. Cypress specifically, not general 'wood mulch'.
safeOrchid barkLong-lasting, holds humidity, resists compaction. Common in tropical vivaria.
safePaper towel or newspaperNot attractive, but correct for quarantine, for a new arrival, and for any animal being monitored for output.
safeLeaf litter over a soil baseCover, humidity and invertebrate habitat in one. Sterilised, from a known source.
safeWith a caveat
Reptile carpetSnags claws and traps bacteria in the fibres. If used, it needs replacing rather than washing, often.
with a caveatSand alone for desert speciesReal desert is packed substrate, not loose play sand. Mix it with soil so it holds a burrow.
with a caveatBioactive setupsExcellent when established, but the clean-up crew needs weeks to establish before the animal goes in.
with a caveatNever
Calcium sand and 'digestible' sandsMarketed as safe to eat, which encourages eating it. Implicated in impaction.
neverCrushed walnut shellSharp fragments, frequently implicated in impaction, with no advantage over soil.
neverPine and cedarSame aromatic phenols as in rodent bedding, and the same airway damage.
neverUncovered heat mats and unguarded ceramic emittersNot a substrate, but the most common cause of contact burns. Every heat source needs a thermostat, and every emitter needs a guard.
neverThis is our general list for reptiles. We have not built one specific to Turtles yet.
Impaction is far more often a temperature problem than a substrate problem: an animal that cannot reach its digestive temperature will not pass what it swallows, whatever it is standing on.
Compare with other animals
The same axes for every animal, side by side — the way the guides are written makes that a fair comparison rather than two articles.
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