You may want to consider a sump.
Super easy to make, relatively cheap, relatively off the shelve
The three containers are dog food and cat litter.
They fit perfectly on the inner edge of the tank.
Home Depot pond filter pumps back t about 850 GPH
Here's a pic of mine.
It's a 40 gallon long as the sump for my 180.
The water comes from the overflows and goes in the three containers.
There's a Rubbermaid basket that's drilled and holds the filter media
The the water hits old school blue bio balls.
There is roughly 12 Gallons of bio balls!!
There is room for another sub filter which would bring me to about 16 gallons of BB.
I was also thinking of switching to the SeaChem Matrix in one or more.
If you'd like more details lemme know.