I have a 20 gallon tank that i want to use for saltwater, so i bought a new filter and everything, and i was just wondering if i could use it in a a 55 gallon, because even though it says made for up to 20 gallons on the box, it says that it also clean 120 gallons up water in 1 hour. Do you think i can use it for now in a 55 gallon until i buy a newer one?