It may be a good idea to take a look at tropical aquariums of fish to understand the equatorial environment and how to mimic it for our pets. It is very reassuring to know that the Malayan box turtle is neither as expensive as many tropical fish nor as sensitive to errors in husbandry. But the "fish guys" at your local pet store can get you started with your vivarium set-up.
Obtain a good sized aquarium. A 20 gallon, long format tank is the smallest
that will allow enough swimming room for one turtle. Keeping two Malayan
box turtles together in the same aquarium is not advised because many can
be quite aggressive, especially males. For breeding pairs, a very large
habitat is required.
Create water and land areas for in the aquarium. The land can be created in many different ways. I elevated the "land mass" on plastic stilts (kitchen racks, actually) so that the turtle could enjoy a larger water area underneath the land. But you could pile up smooth slate rocks into an attractive island. Some owners wedge a thick piece of corkbark at one end for a basking area. With a single turtle of this species, having a very large tank does not seem to be as important as having a comfortable tank, with high humidity and plenty of warm swimming water. They do not like a slippery bottomed tank and may avoid the water if they are unhappy with the substrate. Provide gravel or rocks or some other naturalistic substrate. Some turtle keepers fear gravel because they have heard that turtles eat it and become ill. This will not happen if the turtle has plenty of calcium available (cuttlebone, clean eggshell, etc.) and plenty of fiber in the diet. Turtles do eat gravel in the wild, and it poses no danger to a healthy, well fed turtle.
You will need a water heater, a warming light and thermometers to monitor both water and air temperatures. The top of the tank should be mostly covered in order to maintain high humidity. I use a glass top which has been cut so that it does not interfere with the light. (A UVB reptile light may provide some health and "psychological" benefits for the animal. If some other type of light is used, care must be taken to assure the turtle has enough vitamin D in its diet.) Your turtle will also need a warming incandescent bulb for basking, (not shown in the photo).
Originally, I used a simple Powerhead pump with the undergravel filter. I siphoned and replace the water twice a week. This was not a difficult regimen, but not ideal either. One day Taiping decided he wanted a different system. He pulled the Powerhead out of the filter tube and took it up onto the basking area. I arrived home to the smell of smoke and a horrible noise. The Powehead motor was destroyed. I took that opportunity to switch to a Magnum H.O.T. filter. Because this hangs on the outside of the tank, the turtle doesn't have access to it. I attached the Magnum to the undergravel filter, so the gunk that collects underneath is pulled into the Magnum and filtered. This system works much better. There's more on this filtration method at this link: One effective setup for aquatic turtles in small tanks
While cleaning the filter each week, I put Taiping in another container. During this time I feed him fruits, worms, turtle sticks etc. He gets this big meal just once a week, but always has aquatic plants and/or other greens in his tank every day. He also has frequent access to cuttlebone, allowing him to self-regulate the amount of calcium he needs. Feeding in a separate container helps keep the aquarium cleaner. Taiping cooperates nicely by defecating in the smaller tank right after his big meal.
Most turtles (unlike fish) handle tap water additives quite well. If your tap water is very "hard" or heavily treated with chemicals, you may wish to: 1. use another source of water; 2. use an aquarium water conditioner, or; 3. age the water for 24 hrs. in an open container before putting it in the turtle's tank. Generally speaking, straight tap water is sufficient. Many owners feel the tap water additives are actually helpful in preventing the growth of shell rot pathogens or other harmful bacteria and fungi.
Taiping enjoys his vivarium. He has a dancer's grace in all his actions. He inspects each aspect of the enclosure, occasionally nudging a bit of gravel with his nose (but never attempting to eat it.) He is a beautiful, gentle creature who deserves to enjoy the comforts of the home he left behind in the tropical rainforests of Southeast Asia.
Look at some other set-ups for aquatics:
out Jimmy's tanks