Aquatic Turtles are messy. Very few Turtles are "Mini".
The smallest aquatic Turtles still need a larger tank and can be quite fragile as babies.
They also need haul out areas and
UV and Heat lights.
It's not cheap to set up and they are very messy.
I've had Aquatic Turtles. I managed a Reptile store and as I was checking the incubator an RES egg hatched into my hand

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I rescued a hatchling native Turtle as well. Then rescued a starving Mud Turtle that was "living" in a bucket
Major filtration, water changes, lights, heat, and sun when you can. I loved mine but they needed more room so they went to a friend's outdoor pond with arrangements for winter. Fenced and predator proof and escape proof. It's illegal and unethical to release non natives OR native species that have been in captivity.
There are a ton of Turtles in Rescues. Learn about them and consider offering a homeless turtle a nice tank.
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