Planted tank question...

My corys thrive on CaribSea Sunset Gold sand, my preferred sand and the only one that Jeremy Basch uses in his fishroom. At least one renowned corydoras breeder uses glacial sand (nicely rounded silica particles due to glacial grinding action) which he purchases by the pallet. I was thinking of having the club sponsor a group buy for a pallet of glacial sand if enough people are interested. It would be very cost effective. I'm not sure what the color is but I assume whitish gray.

My C. adolfo colony is currently being kept on fine gravel (CaribSea Peace River), and they are thriving and their barbels are healthy. But I have to stay on top of siphoning or they will run into trouble. This causes angst because it's a breeding tank, so every time I siphon I probably lose a bunch of larval fish. If I kept them over sand, it wouldn't be as stressful. To clean the sand, Rachel O'Leary recommends taking a chopstick and running it through the sand to kick up detritus into the water column and then siphon that. This technique has been working very well for me in other tanks, like the ones where I keep Morse Code Corys.

But in general, most corys prefer to be on sand and leaf litter (with the notable exception of some of the mountain dwellers which are over large gravel and boulders and enjoy cooler temperatures). It's especially important for long-snouted corys to be on soft sand since they have evolved those long snouts to plunge into a soft substrate. On gravel, they aren't able to exhibit their natural foraging behavior. Short snouted corys are better adapted to living over gravel. Just some more food for thought.