Add Yahoo as a preferred source to see more of our stories on Google. Undergravel filters are installed under the substrate, offering a hidden filtration system, but they require regular maintenance ...

We may receive a commission on purchases made from links. Are you confused about the different uses of pea gravel and crushed stone in your yard? That's hardly surprising, since the material can be ...

Explore the pros, cons, and maintenance tips for these unique filters. Reviewed by Nick Saint-Erne Undergravel filters are installed under the substrate, offering a hidden filtration system, but they ...