consolidate totals not averages

[geertn444]

Hello,

I am monitoring my water consumption using Cacti. Every 5 minutes, i read out the meter value.
Every 5 minutes, Cacti puts in the difference between two measurements , divided by 300 (per second) in the RRA.

The problem is that for longer aggregations, i don't want to consolidate "averages", i want to consolidate "totals", ie
total amount of water used every 5 minutes/every hour/every week/every month.

Nobody is interested to know that his "average" use past hour was 30 liters. We want to know the "total" consumption last hour...

Is this possible ?

regards,
Geert