Review on 🐠 Enhance Water Filtration with Powkoo 4-Layer Corner Sponge Filter for Aquariums by Emily Brown

I've searched a lot on Revain and other places. I doubt I saw everything, but it was the smallest sponge filter I could find. So if you're looking for small ones, this is probably for you. The filter itself produces fairly large bubbles, as do other sponge filters. There are videos explaining how to install similar filters on Airstone. Personally, I've decided that I like big bubbles too. Decent quality filter material, especially for the price. If you need an extra small sponge filter for your nano aquarium and like/don't mind bigger bubbles (or don't mind retrofitting an Aeroston), I would recommend this one.