Eastern Mud Turtle — care sheet

Beginner–Intermediate. The care itself is simple and forgiving once the setup is right, and their small size keeps the tank manageable. The catch is the full aquatic rig you have to build first: a heater, a real filter you'll keep clean, a UVB bulb, and a dry basking dock under heat. Get those four things in place and this is one of the easier turtles to keep well; skip any of them and you'll be at the vet.

Omnivore, leaning carnivorous, and a bottom-forager by nature. Base the diet on a quality aquatic-turtle pellet, rotated with protein like earthworms, snails, small feeder invertebrates, and occasional bits of fish or thawed shrimp, plus leafy greens (dandelion, collard, mustard greens) offered in the water. Feed juveniles daily; feed adults a protein meal every other day with greens available in between. Only offer what's eaten in about 15–20 minutes.

A glass aquarium is the tank — this is a fully aquatic setup, not a dry vivarium. Modern best practice for one adult is about 75 gallons, roughly 48"L × 18"W × 21"H, which gives a weak swimmer real room to forage. A 40-gallon breeder is the practical floor for a single small adult, but bigger is always better and easier to keep clean. House only one; never keep two males together.

75–78°F (24–26°C) for adults, held steady with a guarded aquarium heater; keep it below ~85°F. Hatchlings a touch warmer (low 80s °F). Always use a thermometer — never guess.

Moderate depth. Eastern Mud Turtles are only modest swimmers, so keep water roughly twice the turtle's shell length — about 8–10 in for a small adult — with gentle slopes or plants so it can always reach the surface and haul out easily.

A canister or large hang-on-back filter rated for at least 2–3× the tank's actual water volume — turtles are messy and produce a lot of waste. Even with strong filtration, change about 25–30% of the water every 1–2 weeks and keep the flow gentle, since this species prefers calm water over strong current.

A dry basking dock — a floating platform, cork bark, or a stacked rock/log ramp that lets the turtle climb fully out and dry off completely. Aim for a surface temperature of about 85–90°F (29–32°C) directly under the heat lamp, measured with a probe or IR thermometer on the dock itself. Even though Eastern Mud Turtles bask less than sliders, the dry, warm dock is non-negotiable for shell health.

Lights and basking heat off at night. Room temperature down into the high 60s to low 70s °F is fine as long as the heated water stays in its normal range; no separate night heat source is needed indoors at normal household temperatures.

A linear T5 HO UVB tube such as a Zoo Med ReptiSun T5 HO 5.0 or Arcadia Forest 6%, run over the basking dock for 10–12 hours a day. Mount it in a reflective fixture at the manufacturer's distance for the basking zone (roughly 6–9 in with a mesh screen, farther without). Replace the bulb every 6–12 months — UV output fades long before the light stops glowing.

Bare-bottom is easiest to keep clean and perfectly acceptable. If you prefer a planted, natural look, use a layer of smooth, large river gravel too big to swallow, or fine sand for a species that likes to nose along the bottom. Avoid small gravel that can be gulped and cause impaction.

Dust food with a calcium (without D3, since UVB provides D3) supplement a couple of times a week, and offer a cuttlebone floated in the tank for free-choice calcium. Skip vitamin-A megadoses from the pet store — a varied diet plus real UVB covers a turtle's needs, and too much supplemental vitamin A is harmful; correct any true deficiency only under a vet's dosing.

Small — one of the smallest turtles in the US. Carapace roughly 3 to 5 inches (about 78–123 mm); records show males averaging ~94 mm and females ranging up to ~123 mm. It rarely tops 5 inches.

Long-lived: commonly 20–50 years, with individuals living several decades in good care (a documented captive female reached 38 years). Plan for a multi-decade commitment.

See a reptile or exotics vet if you notice: Puffy or swollen eyes, especially with pus-like discharge or an eye held shut — a classic sign of vitamin A deficiency and a reason to see an exotics vet.; Bubbles or mucus at the mouth or nose, wheezing, open-mouth or neck-stretched breathing, or swimming lopsided/tilting to one side — possible respiratory infection or pneumonia; treat as urgent.; Soft, spongy, or misshapen shell, or bowed/weak legs — signs of metabolic bone disease from too little UVB or calcium.; Pits, ulcers, foul-smelling patches, or soft/discolored spots on the shell — possible shell rot; needs veterinary treatment, not just a home scrub.; Not eating for an extended stretch, lethargy, or floating abnormally when it normally sinks and forages — a general 'something is wrong' flag.; Hard swellings or lumps behind the eyes, on the head, or elsewhere — possible abscesses that need a vet.; Any clear deviation from your turtle's normal behavior — when in doubt, call a reptile vet. This is triage guidance, not a diagnosis..