This is a very cheap, very common sponge filter that is mass-produced and sold under many names. I'm experimenting with their use in live food culturing. Here's the configuration I'm using, with the sponges pointing as far down as they can go in the bucket while the lift tube is pulled as far up as it will go. Air flow has been fiddled with to the point there is the gentles stream coming out and breaking surface tension.

Yes, the water is cloudy. That's the daphnia's food.