This is a DIY sump filtration system for freshwater as well as marine aquariums,this type of filter can handle large amounts of bio loads,can be easily built by a hobbyist with only a hand full of tools.

Step 1: Materials Required

1.a box of any kind preferably with a lid[dimensions 8''x4''x5''(lxbxh)]
2.PVC pipe of 1 dia
3.PVC pipe of .5 dia
3.a power head of displacement capacity -300lph
4.filter media.- bio balls,sponge
5.glue of some kind.etc

Step 2: Preparing the Box

make a hole in the bottom side of the box of dia 1 as shown, sand the edges for better glue bonding,can use any epoxy glue,
make some holes to the lid of the box for air circulation

Step 3: Preparing Outlet Pipe and Sump Divider

the sump divider and pipe are shown,pipe can be of any desired length,
the divider is cut so that it fits tightly inside the sump,the divider can be of any material here i hav used foam board.