Ok so apparently I got the older Emperor 400 cause it has the grey thing that goes up and down in the back....and I got it from my technical older brother since he is close to the family in a way. And he gave it to me free with the 55G and stand..but the deal with my Emperor 400 is im a complete noob when it comes to filtration and what not. The deal though is one of my bio wheels is weird and doesn't turn..like at all then the other one is ok but the water when it hits the tank for both of them is just trickling and not a full on flow..so is that normal? Also, what is the impeller and how can I clean it? Some people online I read it is good to clean the motor of the impeller or something? I cleaned the spray bars though cause they were dirty and I poked bigger holes and it improved the filtration by far..but yea if you can help me with this I will glady appreciate it. 
