Original First Flush
After almost 1 year after my cistern upgrade, I went to check the tank after the pollen season and the in tank filter had dropped slightly allowing some of the leaves and significant amount of pollen to enter the tank. This seemed to indicate the first flush was not large enough. The first flush diverts the dust, pollen and other contaminants that land on the roof during fry periods. Once full the a ball closes the vessel and clean water fills the tank. This size first flush was properly sized at 10 gallons to clean the water on the 1000 square foot photo voltaic roof.
Debris floating on the surface
A few leaves resting on the pee trap that slipped out of place and revealing the problem with an undersized first flush.
Pollen
Soot covered filter
This soot covered filter is evidence of too little volume stored in the first flush. Filters used in cleaning water from the city usually have a brown color.
In a few months we should see if the new first flush works.
New First Flush
The new first flush holds about 27 gallons, 3 times the original amount. The water hose on the side was replaced to show the actual level of the water and compare the accuracy to the level indicator on the building dashboard.
To follow Southface’s energy and water usage through their dashboard click here.