Page opened on Wed, 24 Apr 2019 16:14 in New York State in the USA, where the turtle lives.
If the picture is dark, then it's night time here. Turtles are diurnal, which means that they sleep at night just like people do; so the tank lights are on a timer that turns them on and off to simulate daytime and nighttime.
The night video streams run through processing amplifiers ("proc amps") to make the picture seem brighter on the video. It's a lot darker in person. That's also why the night videos look a little grainy.
If you're wondering why there is only one turtle, it's because both of the turtles who used to live in this tank are males, but they are separated in age by a few months. When the older one reached "puberty," it started resenting and attacking the younger one. I had to move the younger one to another habitat to protect him from the older one.
You can see a cached webcam video of the attack itself on this page, which also discusses some other things you should consider before keeping more than one turtle in the same tank; or you can see some higher-quality, pre-recorded videos from when both turtles were in the tank on this page.
This page now uses HTML5 and no longer requires the Flash plugin.
This turtle habitat uses a glass aquarium, which is the most common way to keep aquatic turtles. It uses Flourite as a substrate (which turtles seem to love), with some white gravel as well. It may or may not have some live plants in it depending on whether the turtle has eaten them. It also has a large fake plant. It also may have a few feeder fish swimming around from time to time.
If the water looks cloudy, it could be because there's medicine it it for the turtles or other creatures who live there. Many aquatic medications make the water look cloudy or yellow. When the treatment is done, the cloudiness can be cleared up with water changes and by putting activated charcoal in the filter. It could also just be dust raised from the substrate by the turtles' digging.
If the tank is dark, it's 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. So the white lights get turned off in the evening. There's a blue night light that provides barely enough light for the camera to work. If you still can't see anything, try again when it's day time in New York.
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: