Hi @Scottie68 

Depending on you appliances and when they run while you aren't there could be the factoring reason as to why you see a change from day to day, as example if your hot water system is on electricity and is heating up every other day to keep warm.

With the AGL App you'll be able to view your usage in 30 minute intervals meaning you can view on the days at which time the usage is increasing to assist in identifying where it's coming from.

Thanks, Chris