I use the lacto serum a little differently than most. I start to use it week 3 of flower and use it through the end of flower. I don't use it much in veg. Maybe once.
During flower I will use it twice a week at 1 oz. per gallon of water. It has extremely positive effects on your garden. I will also foliar feed 1 oz. per gallon of water once per week from the start to finish of flower.