Now for the FROTHER, if there is TOO LITTLE frother the bubbles will become small and the speed of the overflow will be slow. If this condition continues the speed will become slower and slower as the collector overloads the bubble. Soon the froth won’t move at all. The colour will remain correct.Flotation Frother Dosage

On the other hand if there is too much frother the bubbles will be large and many of the smaller bubbles will not have any mineral what so ever on them. These bubbles will be the ones that were compressed at the bottom of the cell and by the time they had risen high enough to expand on the surface of the pulp all of the collector molecules will already be attached to a bubble.

This ‘lack of frother’ condition may look very much as though there is too little collector in the circuit except that the speed of the cell overflow will be faster.

Too much frother (over-dose) will cause the cell to overflow un-controllably.  If not enough is frother, you will have holes in your froth bed.  

The imagery below best expresses proper froth dosage from no froth to too much and excessive usage.

How_much_Frother_is_needed_to_add