We just got a 120 or so gallon aquarium. European aquariums are done in liters, so not totally sure on the exact amount of gallons, if they rounded up or down from the decimal and what not. It's filter was broken so we need to replace it. I just saw another forum where people were talking about getting multiple filters to add up to the total gallon amount or more. I would prefer to filter more than the bare minimum, so if this is safe to do, I'd like to go that route. Please help me out here, can I do multiple filters, what are recommended affordable filters.