As a result of using these replacement sponges, I found that my aquarium water is so much clearer and my fish seem to be happier overall. The sponges are easy to install and fit well in my filter.Plus, they`re affordable compared to other water treatment products. MY only con is that these sponges need to be replaced often, but that's to be expected with any pet supplies. Overall, I highly recommend these replacement sponges to any aquarium owners looking for a quick and easy way to improve theiSee full review