that thing in the back corner, is it just a bubbler or is it a filter too?

It could just be a reflection from the plastic but the water looks cloudy, which tells me there isn't a filter or its a poor filter or the filter isn't being used, or ur feeding ur fish too much food.

I've had fish all my life. My papents started teaching me how to care for fish just a couple yrs old. Then when I turned 7 I got my own tank for my bedroom.

My oldest fish was Captain Red, I had him for about 7 years. He would have lived longer, but my neighbour accitently killed him & his tank mate, Jaws & stick. Stick was about 5 years old, he was a weather loach, & Jaws was about 2 years old, he was a green commet.