fishin4cars -- Yes, your info is accurate! Actually, I've had boxies for about 10 years, and these little guys (and girls) are the off-spring on my original pair, both of which escaped before I realized what good escape artists box turtles are!! [Marla, I know exactly what you mean about loosing a pet turtle] The first 2 years I found eggs and left them alone, they were the victims of too-dry soil, ants & other such critters. Then I started bringing them in and incubating them -- that whole process was an education! The trick is to mark the the top of the shell so you know which side is "up." I even took them out periodically and candled them [the eggs] so I would be sure I had viables. There is some, but not a lot of information about the gestational changes [and time tables] that turtles go through. It was interesting to see the eggs go from nothing but a network of blood vessels, to actually seeing little bodies inside: cute little feet kicking, eyes, shell, beak.....!
For my POND, my idea is to have something with the volume of a regular pond, but build in a "false bottom" which would keep the depth for them at a couple of inches. My goal is to NOT have to empty and change their water every single day - sometimes twice a day!! I want to go with biological [and mechanical, or course] filtration, maybe have a few plants.... Been reading up on filters, especially some DIY trickle filters that look interesting. Box turtles are messy -- they usaully always poop in their water!!
I did something like this when they were in their 1st couple of years -- I didn't hibernate [or brumate] them during the winter, but kept them inside in a 55g aquarium. At one end of the tank, I siliconed a piece of plexiglass across the the tank, front-to-back (it was maybe 1/4 to 1/3 of the tank's length), with maybe 10" of depth. Then took some more plexiglass, drilled holes in it (for water & waste to circulate) and raised that up as my false bottom -- used KNEX pieces for supports. When the rest of the tank was filled with substrate and "hides," I made ramps so they could easily get in & out of their "pond." I got an Eheim canister filter, which worked great, except that box turtles make LOTS of waste. Since this was a temporary fix until I could put them outside in the spring, I was more concerned with mechanical rather than bio-filtration.
So, that's my/our story! J.W, I will try for some pictures.