When I woke up this morning, the filter in my tank was making a funny noise. I took it apart and cleaned it, put it back together, and it sounded normal again.
When I got home from work, all the water in the tank was cloudy. This is over the span of 8 hours. I called the local pet shop (not a chain, staffed by generally knowledgeable people), and they said not to worry about it and that I didn't need to change the water. Are they right? What causes this?
For the stats, it's a ~1" turtle in a 10 gallon tank, the water temp is 75, the basking area temp is 88-90, and I had a few guppies in there for him to eat, but I fished out what he hadn't eaten a few minutes ago. There's pebbles on the bottom which my mom put in when she was watching him, but I'm going to take those out since that seems to be what everyone recommends. He has a UVB light.
They told me not to worry, but I'm worried!!!

