Corydoras substrate preferences

[Florence]

What's the best substrate for Corydoras? I've heard mixed opinions on sand versus gravel, and I wanna make sure my lil guys are comfy. Currently using fine gravel, but they seem to struggle a bit when sifting.

[sugarbun]

Sand is the way to go, no doubt. Corys love to dig, and gravel can rough up their barbels. I've got a 20-gallon with pool filter sand, and my Corydoras are always busy sifting through it. Plus, it's easier to clean than gravel.