Yes, it doesn't require more than just a very small and basic pump. And, yes, some sponges actually have an air stone in it. I've made some myself, but many of the ones I've seen on YouTube are very poorly designed. If I ever develop some motivation, I might decide to do a DIY thread on sponge filters. But, as Joe pointed out, they really are very inexpensive already. I got this one for $8 at my LFS...but the picture probably won't work for many of you. It's a Xinyou model...I have it in an aquarium that also has an HOB filter. Whenever I clean the gravel and lots of detritous is floating around in the water, the side with the sponge clears up MUCH faster than the side with the power filter.