I've got a complicated question regarding installing a 2nd cistern.

I have a very low producing well. It now pumps into a cistern. We pay attention
and keep the cistern full. There are times that we travel, or don't use our daily allotment.
I would like to add a 2nd cistern to collect those odd allotments and have no idea how to set up the new cistern.

Is there a way to do this?