I bought an unbranded palm sized hang on the back filter in march and it arrived today, I didn't have high expectations for it as it's unbranded but it works fairly fine... Except for the fact that it literally said "quiet flow" on the box and it's NOT quiet. At all. I think it might be the impeller But as you can see I don't think I can actually remove the motor because it's siliconed to the plastic. So, I'm blank. Any ideas?