Sorry, where is the link?

I've been lookign around, there is a decent amount about waterfalls on this site, I just searched the forums for waterfalls. But I am still trying to decide how to make one that is as sanitary as possible.

Im thinking abot going for a solid back peice agasint the rear of the tank and have the water flow down into a removable water dish, that was it an be removed for cleaning. I am still not sure how to create a back peice that is 100% water proof and easily sanitized.