I use an Absolute CF which is a single pass bowl type. I have two water heaters mounted on a shelf above the CF. With a pump mounted next to the water heaters. I fill the water heater and heat it over night. Then the CF gets turned on and the oil slowly runs into it and out of it into a 30 gallon bucket. The pump is on a timer and after 4 hours it pump the oil back into the water heater and the process starts over again, then again and again the four time I flip a ball valve and it goes into a transfer bucket (30 gal). Every other batch or as time permits I clean the bowl before the 4th pass to see if it leaves anything in the bowl.
The secondwater heater is heating the oil while the first one is cleaning it and the process starts over again I try not to let the CF run for than 16 hours a day.
I used a kil-o-watt meter to measure how much it cost to filter and it worked out to $.03is per gallon I round up to 4 cents. My Jeep cost me $1100 to convert and my Mercedes was about $1000 I used a lot of parts I already had. Of course I purchased two fuel pumps because the first one blew out the seals after 50 gallons. I was thinking of rebuilding it and using it in the biodiesel processor I build but have never used because I needed the pump for my fuel transfer station. I started burning grese and making bio in 2000. Bio did not last very long it just required to much time and work. And that was the early days before upsidedown water heaters and methonal recovery.

Commercial Biodiesel where I live is more than regualar diesel, why would anybuddy that was not a city spending someone elses money pay more for diesel.?