I have a question about fume hood filters for organic vapors. I am a self-employed art restorer and have to replace mine, and it costs $450! Does anyone know of cheaper, generic filters? My husband wants me to go buy some bulk activated carbon and just put that in the old filter. But there are all different kinds- and I really need to get rid of acetone and ethanol vapors. I am pregnant and not in the mood to experiment with my fume hood.