Here's our new carbon filter.
The 4" x 400mm Head will hold around 2.9L of Liquid, but being modular we can always add an extra 4" pipe section for more capacity.
At the base we have a 3/8th inch Needle Valve for nice fine control.
And the 600mm x 1" Upright will hold more than enough Carbon to filter whatever you need. In Standard form as seen here the cost is $225 plus postage.