How Big Do Softshell Turtles Get – A Realistic Guide For Your Aquarium
Have you ever seen a tiny, pancake-flat softshell turtle at a pet store and thought, “That’s the one for me!”? It’s easy to be captivated by their unique, leathery shells and quirky, snorkel-like noses. They look like something straight out of the prehistoric era.
But here’s a friendly piece of advice from one aquarist to another: that adorable little turtle has the potential to grow into an aquatic giant. Underestimating their adult size is one of the most common mistakes keepers make, leading to overwhelmed owners and unhealthy turtles.
I promise this guide will give you the honest, no-fluff truth. We’re going to dive deep into the crucial question of how big do softshell turtles get, breaking it down by species. We’ll cover the massive habitats they require, the common challenges you’ll face, and the best practices to ensure your unique pet thrives for decades to come.
Let’s get you prepared for the reality of keeping these incredible creatures.
Understanding the Softshell Turtle: Not Your Average Pet
Before we even talk about size, it’s vital to understand that softshell turtles are a world away from the common red-eared sliders you see basking on logs. Their biology and behavior demand a different level of care.
Their shell, or carapace, isn’t hard and bony. It’s a tough, leathery covering over a flattened plate of bone, making them incredibly agile in the water but also more susceptible to injury and infection.
They are ambush predators, spending much of their time buried in a soft, sandy substrate with just their snout poking out, waiting for an unsuspecting fish or crustacean. This means they need a very specific type of environment to feel secure. They are also lightning-fast swimmers and possess a surprisingly powerful bite—something to always respect!
How Big Do Softshell Turtles Get? A Species-by-Species Breakdown
Okay, let’s get to the heart of the matter. The single most important factor determining size is the turtle’s species and, crucially, its sex. In most softshell species, females grow significantly larger than males. This is a critical detail that will shape your entire experience.
This section is your complete how big do softshell turtles get guide, focusing on the species you’re most likely to encounter in the aquarium trade.
Spiny Softshell Turtle (Apalone spinifera)
This is one of the most common species in the pet trade, recognizable by the small, spine-like projections at the front of its shell. The size difference between males and females here is staggering.
- Males: A manageable 5 to 9 inches (12-23 cm) in carapace length.
- Females: A massive 7 to 19 inches (18-48 cm)! That’s the size of a large dinner plate.
If you get a female Spiny Softshell, you are not planning for an aquarium; you are planning for an indoor pond.
Smooth Softshell Turtle (Apalone mutica)
As their name suggests, Smooth Softshells lack the spines of their cousins. They are also quite common but still reach an impressive size, especially the females.
- Males: A smaller 4.5 to 7 inches (11-18 cm).
- Females: A substantial 6.5 to 14 inches (16-35 cm).
While not as gigantic as a female Spiny, a 14-inch turtle is still a very large animal that requires a huge habitat.
Florida Softshell Turtle (Apalone ferox)
This is the undisputed heavyweight champion of North American softshells. They are known for their aggressive nature and their truly colossal size. Honestly, these are not suitable for indoor aquariums as adults.
- Males: A respectable 6 to 12 inches (15-30 cm).
- Females: An absolutely giant 11 to 24 inches (28-61 cm), with some reports of even larger individuals.
A two-foot-long turtle is a pond animal, period. It’s a serious commitment that very few hobbyists can properly accommodate.
Chinese Softshell Turtle (Pelodiscus sinensis)
Often sold in the trade, this species is a bit more reasonably sized than its American counterparts, though still no small pet. The size difference between sexes is less pronounced.
- Males & Females: Typically reach around 10 to 13 inches (25-33 cm).
While more “manageable,” a 13-inch turtle still needs a very large tank, far bigger than what most beginner aquarium kits offer.
Planning Your Habitat: The “Rule of Thumb” and Why It Matters
You’ve probably heard the old rule of “10 gallons of water per inch of turtle.” For active swimmers like softshells, I’m here to tell you that’s the bare minimum starting point. They need space to swim, turn, and, most importantly, a large floor area to bury themselves.
A better approach is to think about the tank’s footprint. A long and wide tank is far more valuable than a tall one. Here are some more realistic housing how big do softshell turtles get tips:
- For Adult Males (Spiny/Smooth): A 125-gallon aquarium (72″x18″ footprint) is a good starting place.
- For Adult Females (Spiny/Smooth): You should be looking at 200-gallon tanks or, even better, large stock tanks (like Rubbermaid’s 300-gallon models) or custom-built indoor ponds.
- For Adult Florida Softshells: An outdoor pond in a secure, temperate climate is the only truly appropriate long-term home for an adult female.
Remember, you must build the enclosure for the turtle’s potential adult size. Don’t buy a hatchling thinking you’ll upgrade “later.” Life happens, and the turtle is the one who suffers in a cramped tank.
Common Problems with Housing Large Softshell Turtles
Understanding the potential challenges ahead is a key part of responsible ownership. This isn’t to scare you, but to prepare you! Addressing these common problems with how big do softshell turtles get head-on is the secret to success.
1. Massive Filtration Needs: Large carnivorous turtles are messy. They produce a ton of waste. Your standard hang-on-back filter won’t cut it. You’ll need a powerful canister filter (or two) rated for at least double your tank’s volume, or a sump system, to keep the water pristine.
2. Shell Health Issues: Because their shells are soft, they are prone to fungal and bacterial infections if water quality is poor or if they get scratched by sharp rocks or gravel. This is why a fine sand substrate is non-negotiable.
3. The Need for Perfect Basking: They need to fully exit the water to dry off and absorb heat and UVB light. This prevents shell rot and helps them synthesize Vitamin D3. You must provide a large, stable basking dock with a heat lamp creating a 90-95°F hotspot and a separate, high-quality UVB bulb.
4. Potential Aggression: Softshells have a powerful bite and a long neck. They can be aggressive towards tank mates (they will eat any fish that fits in their mouth) and can deliver a painful bite to an unwary owner. They are best kept alone and should be considered a “look, don’t touch” pet.
A Complete Softshell Turtle Care Guide for Healthy Growth
Providing the right care from day one ensures your turtle grows up healthy and strong, reaching its natural adult size without complications. This is your essential how big do softshell turtles get care guide.
The Ideal Enclosure Setup
Beyond just size, the details of the habitat are crucial.
- Substrate: Use 2-4 inches of fine-play sand or very fine aquarium sand. This is essential for their mental and physical well-being, as it allows them to bury themselves. Avoid gravel at all costs.
- Decor: Smooth driftwood and rocks can be used, but ensure there are no sharp edges. Prioritize open swimming space.
- Water & Lighting: Keep the water temperature between 72-80°F. Provide a high-quality UVB light (like a T5 HO linear bulb) over the basking area, replacing it every 6-12 months as recommended by the manufacturer.
Diet and Nutrition for a Growing Giant
Softshells are primarily carnivores. A varied diet is key to their health.
- Staple Diet: Start with a high-quality commercial aquatic turtle pellet.
- Protein Variety: Offer earthworms, crickets, ghost shrimp, and occasionally pre-killed feeder fish from a safe source. Avoid wild-caught prey, which can carry parasites.
- Feeding Schedule: Feed juveniles daily, and adults every other day to prevent obesity, which can be a serious health issue.
Sustainable & Eco-Friendly Practices for Softshell Turtle Keepers
Part of being a great aquarist is being a responsible one. Adopting sustainable how big do softshell turtles get practices is crucial for the hobby and the environment.
First and foremost: NEVER release your turtle into the wild. It is illegal, cruel to the animal (which is not equipped to survive), and can introduce invasive species and diseases that devastate local ecosystems. If you can no longer care for your turtle, contact a local reptile rescue or herpetological society.
Always choose captive-bred turtles from reputable breeders. This reduces pressure on wild populations and ensures you get a healthier, more well-adjusted animal. This is one of the most important eco-friendly how big do softshell turtles get choices you can make.
Frequently Asked Questions About Softshell Turtle Size
How fast do softshell turtles grow?
They grow incredibly fast in their first two years, often reaching half their adult size in that time. Growth slows down considerably after that, but it does continue slowly throughout their 20-50 year lifespan.
Can I keep a softshell turtle in a 75-gallon tank?
A 75-gallon tank is only suitable as a temporary home for a hatchling or juvenile. An adult male of a smaller species (like a Smooth Softshell) might manage, but it’s not ideal. Any adult female will require a much, much larger enclosure to thrive.
What is the smallest species of softshell turtle?
While some truly small species exist, like the Malayan Softshell (Dogania subplana), they are very rare in the pet trade. Of the commonly available species, a male Smooth or Spiny Softshell will be your smallest option as an adult.
Does the tank size affect how big a softshell turtle gets?
This is a dangerous myth. A small tank does not healthily stunt a turtle’s growth. Instead, it causes immense stress, skeletal deformities, organ failure, and a painful, premature death. You must always provide a habitat suitable for their maximum potential size.
Your Journey with a Gentle Giant
So, how big do softshell turtles get? The answer is: bigger than you think! Especially if you end up with a female. They are not a casual pet but a serious, long-term commitment that requires significant space, investment, and dedication.
Don’t let this discourage you, but let it empower you. By understanding their true needs from the start, you can make an informed decision and prepare to provide a fantastic home. Watching one of these magnificent, prehistoric creatures glide through a spacious, well-maintained habitat that you created is one of the most rewarding experiences in the entire aquatic hobby.
Plan ahead, build big, and you’ll be on your way to successfully keeping one of the most unique reptiles on the planet. Happy fishkeeping!
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