I was doing some thinking the other day and would like to know what you guys think.My dad was in the water treatment buisness for about 20 years therefor I got to thinking about the equiptment and material that was used to neutralize acidic water. the material was basicly crushed oyster shells and that is basicly all calcium. this substance would raise the PH of water from anything from a 4.5 up to a neutral 7.0 just by passing through it. that being said here's my question.. Would this stuff work on wvo to bring up the PH from high FFA. would it have any adverse affects on the oil or Biodiesel production. I plan on trying this by perculating the oil through a mixture of calcite and this oyster shell material. I want to try this due to the crappy oil that I've been getting lately just as another option for high titrate #s. I do know that the material would desolve into the water to raise the ph and then was filtered out leaving ph 7.0 water. I wanted to get some feedback as to what you guys "fabman" thought about this and if you think it will work. thanks for any info and I'll post some results once I try it this weekend. the material is about $50.00 for 50 pounds but it lasted for several thousand gallons of water, maybe it will work for WVO.