Pause Period (no water is flowing)
The water will stop flowing when the standing water level is at the same height as the end of the outlet tube.
Some oxygen from the air diffuses through the standing water to the biolayer during the pause period.
The pause period allows time for micro-organisms in the biolayer to consume the pathogens and nutrients in the water. Pathogens in the non-biological zone (below the biolayer) die off due to a lack of nutrients and oxygen during the pause period. The pause period should be at least 1 hour.
What Kind of Water Can I Use?
Clear water - The filter will work well. You will not have to clean the top of the sand very often.
Dirty water - After a few weeks, the filter will start to flow slowly. You will have to clean the top of the sand sometimes to make it flow faster.
Very dirty water - The filter will quickly start to flow too slowly. You will have to clean the top of the sand often to make it flow faster.
If the water is very dirty, settle the dirt out of the water by letting it sit in the bucket for a few hours, do not use the dregs from the bottom of the bucket.
Always use the same water source in the filter
Optional: Download English 'How the BioSand Filter Operates' Handout #3
SOWING SEEDS OF SUCCESS - MORINGA CURRICULUM