1600 GPH duel over low with prefilters. Aqualifter with prefilter for instant prime. Customization includes tops w/ straws on the water inlets to stop any gurgling and an acrylic top to further reduce water movement noise.
30 gallon sump. From top left - 2 inch thick course sponge prefilter with a filter mat laying on top to catch large debris. 2nd comartment (trickle), bio filter mat. 3rd comartment 3 inch square sponge. 3rd compartment, and 4th where the pump inlet is are currently clear from filter media. At the end is an an external 1200GPH pump filtering a 140 gallon tank. I use these last compartments for paramiter buffers and what ever else I can think of like CO2 defusers. There is also a water top off line. You can just make it out as a white water line with a black sponge on the end to defuse water pressure. I also have an LED pendant attached to the rim. I'm currently growing plant clippings in these last 2 comartments. The filter in the fourth compartment only catches potential plant debris from plants growing in the sump.
The second compartment is where one would put bio balls if they had them. After research I found this 2 - 3 inch bio filter mat at a local Koi garden store. With research it is said to have more surface area than bio balls. So I went with this bio mat. Its been in there about 7 years now.