Jerry You can remove those deposit by soaking it in distilled vinegar or by using one of those green scrubby things ( brand new one of course), soaking it in vinegar and scrubbing the deposits off. I use vinegar to clean old african rift lake tanks to remove the build up hard water deposits. It really works well. A little elbow grease goes a long way, a household product sold in stores called CLR is supposed to do the same thing, but i dont know if it would be safe for aquarium use or not. John ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!