Overview of the sump under the stand all setup an ready to fill up with water

A view of the tower from the front with everything in place.  There are 2 towers, with 2 overflows from the tank, one overflow feeding one tower.

Starting from the top, you can use any type of media to catch the solid waste.  I used A/C filterpads made for A/C window units and cut them to fit my drip tray.

I had a huge roll of another type of drainage fabric with plastic backing so I decided to go ahead and use it.  Can't hurt anything right??

Next is the drip tray.  I made mine out of Plexiglass/acrylic that you can get in sheets from Home Depot or Lowes.  It cuts easily on a table saw or with a circular saw.  The drip tray has a lip around it to collect water to slow down the fall rate through the bio-balls.  It also has holes drilled to drip over the bio-balls, size will vary depending on your pump rate, but it is best to start small and go bigger if needed.  Making nice clean holes in the acrylic can be tricky but it just takes patients.  Start with a small pilot hole and use a Uni-bit/step bit to make it bigger as needed.

These are 2 tier towers that I picked up at The Container store.  Basically any storage bins will work, there isn't a set size you just have to buy what will fit in your sump and under your stand.  You will also need to drill holes in the drawer of the container to drip down into the next level of your tower.

This is probably not necessary in most peoples opinions, but I wanted to fill the bottom drawer up to quiet the noise down from the falling water and the extra surface area doesn't hurt in my opinion.  From the top down this is just a piece of cut to fit foam pad that you can pick up from a fabric store.

Then I cut to fit a piece of eggcrate that you can get from HD or Lowes

Then comes the safety fence..:)  I had alot of this stuff in my shop so I figured I'd go ahead and use it up.  Cut to fit in the drawer and stacked until I had enough to fill the drawer with that the eggcrate and the foam.

Again don't forget to drill holes in the bottom of the drawers top and bottom tiers of your tower.  The grid just keeps it neat.

That is the main filtration of the W/D filter, the water trickles through that back into the main tank and then your submersible pump pumps it back into the tank.

Sumps can store all the unsightly heaters, thermometers and other misc. things you may have in your tank.

You can also make up your own  filter bags containing carbon or whatever you decide you need to use, can be stored in your sump.