Bought from US. Just test but haven't use as I change to Canister filter finally.

The Easy Seachem Tidal Filter Optimizer is a 3D-printed upgrade for Seachem Tidal hang-on-back filters that replaces the stock intake system. It removes the built-in surface skimmer and redirects all water through a single intake, allowing the use of a pre-filter sponge. This helps prevent shrimp, fry, and floating plants from being sucked in, while also reducing debris entering the motor and improving filter longevity. It can also make the filter quieter and more stable at lower water levels, though very small fry may still require extra protection.