The FOAM SPONGE FILTERS by Aquacadabra are designed for aquarium breeding fry fish tanks, specifically the XiJ-380 model. These biomechanical filters are suitable for all water types, providing a safe and effective way to keep the water clean and healthy for your fish. The large sponge filters offer a gentle filtration process that is ideal for fry fish tanks, ensuring a clean and stable environment for your aquatic pets to thrive.