Unless you're buying your metalworking fluid from your brother-in-law, you probably don't want to buy new fluid every week. So your choices are to 1) recycle it, 2) recycle it, or 3) recycle it. Eventually you will have to dispose of it and no one in the world can agree on the easily measured conditions for this. That current standard remains a modified version of the Supreme Court's test for pornography - 'You know it when you smell it.' Until the faithful day that a volume of the fluid will be sent to the great beyond, your goal is to maintain the fluid in the best possible condition. (We should treat ourselves so good). You need to monitor it and medicate it properly when needed. It's an important job and excellent and capable equipment is needed for that job. It also requires the right size equipment. You don't want a recycling machine that is undersized, or one the cost more than just disposing of the fluid every week, regardless of how socially responsible you are. Eriez is in this business and has several stationary machines sized nicely to fit convenient intervals of manufacturing magnitude. Their CRS machines have varies levels of capacity and capability. From the 120 SS (120/160 gal dirty /clean ratio) to the CRS 300ST (300/450 gal ratio) and a multitude of advanced features. This is a good place to start shopping.