i have been given a filter and i want to know which tank i should put it into. its an eheim aquaball 2208510, i think. thats what its says, but i dont have any bits for it. it has a tubular sponge and a smaller compartment which i presume is for carbon or something. its says the turnover is 480 lph. i have a 66 litre tank and a 91 litre tank. which would it be best for?