The idea is to move the wine from one tank to another so as to separate the wine from the lees or sediment ('gunge') that has settled on the bottom.
We also clarified the wine using organic egg-whites. We used 2 egg-whites per 100 liters of wine to be clarified. This is done to remove all the tiny suspended particles ('bits') that are too light to drop to the bottom by gravity. Egg-white has the property of making these tiny particles stick together, so they become heavier and drop to the bottom in about 10 days or so.