Aqueon Feed Hole Plug

thingiverse

The Aqueon tank lids feature a convenient feeding hole that lets you easily nourish your fish without having to remove the entire lid. However, this ingenious design comes with a drawback - it accelerates water evaporation and inadvertently provides an escape route for some curious fish. This compact plug is specifically designed to fit snugly into place and can be effortlessly removed whenever it's time to feed your aquatic friends.