Fits and works just like the original Tetra brand
These are just as good as the Tetra brand and a lot less expensive. They work really well for my fish tank that has 4 large goldfish. These fish have grown too large and now require weekly water changes to keep the water fresh. I change these ammonia filters out when I cha ge the water and they do great job of helping keep the water safe for the fish. If I forget to change it, it’s immediately noticeable, with the fish clinging to the top of the tank. As soon as I cha ge it, you can see their almost immediate relief. Read more
