Easy Aquarium Safe Sponges?

[LindsayLuFoScho]

Hey everyone! I'm trying to find a quick and easy aquarium safe sponge. I need to plug some holes in the sides a tank divider I made for some babies. After some research, I know that kitchen and makeup sponges aren't safe. Does anyone have any suggestions on what I could use?

 

[Herpin Man]

You could probably find a sponge or other filter media that would work at a tropical fish store.