The Fluval Foam Blocks are designed for use with Fluval canister filters, specifically models 204, 205, 206, 207, 304, 305, 306, and 307. These foam blocks come in a 2 pack and are suitable for aquariums with a tank capacity of 40 gallons. They are designed to filter all water types and are located externally in the filter system. These blocks are essential for keeping the water clean and clear in your aquarium, providing a healthier environment for your fish.
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