xp3

This is how I would put in a XP3.

Bottom tray - sponges
Middle tray - biomax
Top tray - biomax

i got it to be more of a mechanical rather than a biological. I will probably have a bio-wheel hob to help it out anyway and the tank will be planted.
 
My XP3's both have the stock sponges in the bottom tray, middle tray is filled with Seachem Matrix, top has the Biozorb in the bottom (which will probably get tossed in 2-3 months), top of tray has floss pads and the Rena micro filter pad.

Works for me!
 
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