Review on Penn Plax Smallworld Filter Cartridge by Michelle Powell

My mother decided she needed a female betta but decided against a large aquarium. I didn't want to have to keep changing the water, so I went looking for a filter. I chose this filter because I liked that it doesn't take up much space in the aquarium. seems to work great for a 1 gallon tank and there is very little flow. The betta is happy, so is my mom, and I don't have to keep changing the water, so I'm happy too.