Hello Edison if you are looking for exact gallonage of water that you have, the formula for that is : height ( in inches ) x width ( in inches ) x length ( in inches ) divided by 231 = total gallons of water. Hope this is what you were looking for. 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"!