[Mrmofo]

you need the filter to pump out minimum 6 times the whole tank capacity an hour. you also need to MOVE 20-30 times the tank capacity per hour aswell. if u have a 100 litre tank, u need to filter(6 times) 600 litres and hour and move say (25 times)2500 litres n hour around the whole tank.thats what the lfs guy told me and i have crystal clear water

 

[Mrmofo]

to not create dead spots try to have minimal surface area touching the sand where i mean if u have a triangle piece or somthing u put it on the angle instead of the flat piece so water flows over it. 1 power head really isnt enough u need atleast 2 bare minimum to move the water from all spaces high n low