I have decided to switch to pool filter sand, since trying both play sand and filter sand. The pool sand has a much larger granule size, and the grains are very round...much like very tiny balls. It is my opinion that when ingested, these larger rounder granules would be more apt to pass through the gut, rather than pack in. Really, with collareds in general, impaction has not seemed to be real problematic with anyone on this site, with the exception of a couple. The filter sand is closer to $9.00 for a 50 lb bag.