These valves control how the water is managed:
The Primary tank is on the right, the secondary tank on the left. An electric pump extracts water.
the clear pipe is the water gauge and the light blue pipe is the house supply.
This 'valve farm' provides control of the water harvesting system. Water can be 'balanced' by opening the two tank valves. Selective feeding is achieved by opening one tap. The fire-fighting supply is also valved. The small clear hose is a water gauge and opening just the valve of one tank reads its contents.