Adding Lemon Juice and Nutrient/Energizer before SG 1.050

[kiphorn]

I started a batch of SP on Saturday afternoon and added the yeast slurry this morning. We're leaving Friday around lunchtime for the long Memorial Day weekend. Not sure how long it will take for the yeast to get active and for the SG to drop to 1.050. If the SG has not dropped by the time we leave, would I be better off adding the last of the Lemon Juice and Yeast Nutrient/Energizer before I leave or on Monday night. Looking at best option for avoiding the sulphur dioxide issue.