You mean Hydroballs? They are basically the same as Hydroton, only require a bit more rinsing and are darker. I like the way those look better, honestly. Both Hydroballs & Hydroton are an expanded clay substrate... I don't really see the difference. I'll take ZM Hydroballs over gravel any day.Zoomed's Hydrogen Balls-Worst
Worst Substrates: "Organic potting soil", straight coconut fiber, and straight peat.