3 months ago, I bought 2 such filters, for myself and my sister. Both have the same problems. Actual production of 300!!! liters instead of 1200 liters per hour! This is a 4-fold deception. After cleaning, it takes several hours and a lot of patience to start the filter again and expel the air from the inside. The aeration is also unreliable, sometimes it stops working, my fish almost died. Plastic accessories of low quality. I do not recommend!