Turnover really is a poor benchmark to use for proper level of circulation, but is handy in estimating correct sizing for a pump when under construction. Need for filtering will vary considerably from pool to pool depending on a number of factors (type of debris, use, shape, weather, circulation patterns, etc.) So instead of worry about turns per day or any such thing, it is much better to start at some X hours per day and judge if the water is remaining clear, if skimming action is removing surface debris, etc. Then keep turning that down until you start to notice issues, and bump it back up plus a little safety margin, and that is the amount of time you need to run your pump.
ps speed for a variable speed pump, can be set at a minimum level that provides effective skimming and circulation