The 120 can handle up to 200gal system. It holds 700ml of media which is enough to provide results for a 120-180gal depending on the demand of the aquarium. With a water volume of approximately 160gal you will likely only need 600-700ml. You can still go to the larger model 150 which holds 1000ml and dial down the aquatrance feed pump to slow the churn down for lower media levels as well.