Gone are the days when the filter element and filter media were replaced almost every week. The convenient filter will complete the same work economically and quickly. Specially designed for FRY and other small aquatic animals - betta, fry and other small fish will never get stuck in the filter. These fish, especially the betta, usually don't like the turbulent water, they like the calm and stable water. This filter is designed to have a slow current so that the betta, goldfish discus, dwarf cichlid, peacock and krill can continue to breed and spawn comfortably. This will encourage them to continue to reproduce and lay eggs in comfort. In addition, the sponge filter provides a home for supplementing fish food in daily diet or food intake. When used alone, it can hold up to 10.5 gallons of water tank - it only needs air pump and air pipe (sold separately) to work. This will produce a large number of tiny bubbles and increase the oxygen flow. Simply connect the air pump to the top center of the filter and place it in the tank. Please note that the base of this noise-free filter is not weighed, so you may need to weigh it. It is applicable to tanks below 10.5 gallons. Use 2 or more filters in larger tanks. Easy to clean and reuse - this low-cost sponge filter can be used many times. When changing water, use the water in the water tank to clean, instead of running water. Just rinse and squeeze a few times until you see water flowing out of the sponge.