Abstract: A liquid reconditioning system including first and second storage tanks for storing reconditioned liquid and liquid to be reconditioned, respectively. Reconditioned liquid is withdrawn from the first storage tank for use, as required, and returned to the second storage tank. A filter is connected to receive liquid withdrawn from the second tank to filter that liquid and transfer it to the first tank. The present invention detects a condition representative of filter blinding and responds to that condition to automatically regenerate the filter. In a preferred embodiment, the filter is a diatomite filter with filter regeneration being accomplished by mechanical diatomite displacement. A valve at the filter output closes that output during diatomite displacement and then sequentially connects the filter output to the second storage tank, for a predetermined period, and then to the first storage tank.