I never heard it should be avoided. I only heard that while axies (juvies or adults) may swallow, the risk of impaction related illness and injury are menial as they are usually able to pass it. They have silt ot rocks in the natural habitat and I use heavy play sand that does not unsettle easily. Thanks for the concern.Little cuties. I'm certainly no expert......but shouldn't sand be avoided until they are bigger......I understood it can cause impaction in babies like gravel in adults.......