Sump advice

[Wobblebob]

Hi guys.
So I’ve just brought myself a 400l tank with a 100l sump. I’ve never used a sump before and was after some advice on media to use and placement etc.
It’s got 3 chambers plus a top up chamber (used to be used for marine but I won’t be using this chamber) I have a filter sock on the pipe letting water into the sump but am stuck with what media to use and whereabouts to put it. I’ve spoke to someone a my local LFS and he advised me to put pond filter media (black, green and blue foam egg crate style sheets) in the middle chamber. I have done this but can’t see how this is going to filter anything considering the water doesn’t pass through them rather just over the top. I’ve attached a pic of the sump layout and any advise anyone can give will be greatly appreciated.
Thank

 

[rlederer]

What you need to do is put the filter media on the left hand side - where your arrow shows inflow. fill the bottom half or so with bioballs or something like that to grow a bacteria colony on. On top of that you need a square of plastic eggcrate mesh or the equivalent. Then put a mesh or felt pad or two over that. I use a 100 micron felt pad on the bottom and top it with a 50 micron pad about half the size of the 100 micron. The pads need to be above the water level so the incoming water flows through them.
Then, once a week, change the pads. Never have to touch bioballs. Easy once you get it set up.

 

[Wobblebob]

Nice one, thank you.
What size balls would you say? And any particular brand or are they all as good as each other?

 

[rlederer]

I don't think the size makes too much difference. I've only seen two sizes, one about the size of a jawbreaker and the other the size of a golf ball. I'd go for the big ones because in the rare event you have to take apart the sump, it's easier to deal with the large ones.