It has recently come to my attention that my brand new Interpet PF1 is not clearing the water sufficiently in my 10 gallon tank. This is the first time I have used an internal filter because on my other tank I use an external filter. It doesn't actually suck in any debris even when on the strongest setting. The current of the filter just makes the floating debris cycle endlessly around the tank making it even more dirty. The intake of the filter only seems to suck in water but nothing else. Any suggestions?