.answer li {list-style: inside;}.embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%;} .embed-container iframe, .embed-container object, .embed-container embed, .embed-container video { position: absolute; top: 0; left: 0; width: 100%; height: 100%;}HydroBalls Expanded Clay Terrarium Substrate can be used as a base layer underneath Zoo Meds Eco Earth® coconut fiber substrate or other substrates to create an underground water table in Naturalistic Terrariums. Add water to create a natural "aquifer" and increase humidity levels for all tropical species. Excellent substrate for live plant root growth in Naturalistic Terrariums. Use for filtration for a waterfall. Need screen to seperate the Hydroballs from your substrate? Try out fitted Zoo Med Terrarium Mesh.