Aqua Tech EZ-Change Replacement Filter Cartridges #3 6 Pack

I bought the wrong size:/ 4.5"D x 6"W x 6.75"H The first stage of the AQUA-Tech filtration is mechanical. The blue polyfiber pad that is integrated onto the EZ-Change Filter Cartridge screens out dirt and debris as water passes through. The second stage of the AQUA-Tech filtration is chemical. The activated carbon that is in the EZ-Change Filter Cartridge removes dissolved waste and cleans the water of odors. The third stage of the AQUA-Tech filtration is biological. The BIO-Fiber that is included in each AQUA-Tech Power Filter provides additional surface area for beneficial bacteria to grow and thrive. The bacteria then eliminate toxic ammonia and nitrites that can be fatal to fish. You should never clean or throw away the BIO-Fiber. If the BIO-Fiber becomes too clogged, rinse it with conditioned water only.