hi new to saltwater/reef tank. began my set up after preliminary research. Went to local store and purchased six 4.4 gallon (= 26.4 gallons) RO DI water jugs bc i read biocube tend to take less than stated amount plus water displacement. filled it with four jugs added 30 pounds sand and about 25 pounds live rock and it's totally full. how can that be? I've read on forums 26 gallons 25 gallons even 22 gallons but 17 gallons? any thoughts? any help would be greatly appreciated.