My sump has the following in order from where water goes in back to pump. The cermedia makes a mess in my sump it seems to have fine particles all over the sump, I guess it just what the stuff made out of. I would like to replace it what would you guys replace it with more Pond Matrix or bioballs or something else?

4 filter socks
Filter Floss
4 layers of poret foam
Cermedia Marine Pure Bio balls media
Seachem Pond Matrix (several buckets full in a bag)
1 layer of poret foam to protect pumps
Return Pump/CO2 Pump/UV Pump

I have 4" of foam, varying thicknesses. Then a bunch of scrubbies and seachem matrix that I had in my canister before. After that, it is just heaters and return pumps. KISS. Is the tank crystal clear? No, but I don't mind.

I'd say look into foam pads, which make great bio media, or dollar store scrubbies. They both have incredibly value for bio media. Bio balls are usually used in a wet/dry setup, right? Mine is fully submerged.

The ones I want to replace are fully submerged as well, don't get me wrong the stuff is great just makes a mess. I will have to check out the scrubbies.

Thanks

I've just started cycling my sump that is going to get setup over the winter.

It has (in order):

2" 10ppi poret foam
2" 20ppi poret foam
4L Seachem Matrix
500 ml Seachem Purigen
Filter Floss
2" 20ppi poret foam

All the water has to pass through the filter floss and last sheet of foam before it can get to the return pump area, so water is getting pretty clean. I've been really happy with Matrix as biomedia, it doesn't really seem to break down.

-Justin