I'm preparing to upgrade my parents' 29g to a 55g, and one of the changes they've requested is to switch to white sand instead of the black gravel they have now. I've encouraged the switch since they have cories that would love the sand, but I have read some accounts of white sand growing algae. Their tank already has a bit of an algae problem from excess light (they have a big window in the room where the aquarium is) but they have nerite snails to eat the algae. Can the nerites eat algae off sand? Petsmart (the only fish store in my city) also sells a cork colored tan sand, so I wonder if that might hide the algae better if the snails can't eat it. Thanks in advance for any help!