Imagine Gold Llc AIM78015 Bio Power Filter with Skimmer, 15gal Imagine Bio Pwr Fltr W/Skmmr 15gal 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 15gal 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 15gal Removes organic film and dust from the water surface