Secondary treatment vermifilter construction
Low cost wastewater treatment for the world
Use the system design page for guidance on design.
The construction pages:
recirculating secondary treatment vermifiltration
settling tanks; and
treated effluent distribution to surface irrigation using a pump.
Constructing vermifilters (for secondary treatment)
Constructing vermifilter from 250 litre plastic drum
Plastic oyster mesh. This is available as tubes, perfect diameter for 200-250 litre plastic drums
Textile cloth stitched to the inside of the oyster mesh.
Inserted into drum
Bark media added
Plastic drainage coil spacers added. This keeps the vermifilter centralised and with good air flow right around it.
Recirculating secondary vermifilter powered by a solar panel:
The vidoes above shows a domestic vermifilter with active recirculation using a battery, timers and solar panel.
Setting up solar-powered recirculating vermifilters
Solar vermifilters are designed to run intermittently, for example ten seconds every minute, twenty four hours per day. Four components are required: the pump, the solar panel, the battery and the timer.
1. Pumps
Recirculating pumps suitable for solar vermifilter systems:
Recommended: Whale gulper 220
The secondary vermifilter requires a pump suitable for recirculating water with high levels of suspended solids.
12 volt DC, no clog, no filter waste pump, large single diaphragm, 12.6 litres per minute with current draw of 4 amps at 1m head. 19mm hose connections. Max discharge head of 3m.
Recommended: 19 watt brushless centrifugal water pump
The tertiary vermifilter requires a pump suitable for recirculating water with low levels of suspended solids.
12 volt DC, 800 litres per hour, maximum discharge head of 5m, 1/2" male threads, 1.6 amps
2. Battery and timer
A single battery is required, along with separate timer controls for each recirculation pump. The timer operates the recirculation pumps intermittently.
Recommended: 12.8V 21Ah Lifepo4 battery pack (4S3P, with 12x 32700 cells)
Overvoltage and undervoltage protection are required. The Small Den battery available on Ali Express has Discharge Cutoff Voltage: 10 +/- 1V and Charge Cutoff Voltage: 14.6V, with a 40 amp balance BMS suitable for direct solar charging
Cost approx. US $100
Recommended: JZ-801 or XY-J02 Cycle Delay Automation Timer Control
12 volt, low power consumption, provides a separate "on" time and "off" time.
Cost approx. US $4
3. Solar panel
A single 50 watt solar panel is sufficient for intermittently running a secondary recirculation pump and a tertiary recirculation pump.
Make sure to use a nominal 12 volt solar panel for a 12 volt system.
Cost approx. US $100 for a 50 watt solar panel.
4. Assemble the components
See the video above for how these components can be put together in a working recirculation system.