This turtle habitat uses a glass aquarium, which is the most common way to keep aqauatic turtles. It uses Flourite as a substrate (which the turtles seem to love), with some white gravel as well. It also has both rooted and floating plants, but the turtles usually uproot or eat the rooted ones. It also may have a few feeder fish swimming around from time to time.
If the tank looks dark, it's probably because it's night time. Turtles are diurnal animals like we are, which means that they usually sleep at night, and they need light / dark cycles. There are two blue nightlights that provide barely enough light for the camera to work, without keeping the turtles awake.
Although the exact equipment may change from time to time because of seasonal changes, health issues (sometimes turtles get sick and need the temperature raised for them), and other reasons, the basic setup that I usually return to when everything's back to normal is as follows:
Tank Size: 75-Gallon
Water Volume: Approximately 62 gallons
Filtration: 1 Hagen Fluval 305 Canister Filter and 1 Exo Terra Flo 350 Internal Filter, which is used for additional filtration and as a circulation pump.
UVB / Basking Light Source: Exo Terra Solar Glo Sun-Simulating Lamp
Substrate: 60 lbs. Flourite
Temperatures: Water = 78 degrees F. Basking area (daytime) = 88 - 92 degrees F.