Imagine Gold Llc AIM78025 Bio Power Filter with Skimmer, 25gal Imagine Bio Pwr Fltr W/Skmmr 25gal Removes organic film and dust from the water surface. Delivers oxygen rich surface water to the filter which enhances the growth. of nitrifying bacteria. Imagine Bio Power Filter W/Skimmer 25gal Removes organic film and dust from the water surface Delivers oxygen rich surface water to the filter which enhances the growth. of nitrifying bacteria Imagine Bio Power Filter W/Skimmer 25gal Removes organic film and dust from the water surface