I'm thinking out a project that'll make RO water for me, wifi controlled of course.
1x normally open solenoid for permeate
2x normally closed solenoid 1 for flow restrictor bypass (membrane flush) and 1 for permeate-to-drain
1x electric ball valve for feed water
1x low pressure switch
1x high pressure switch
associated control circuitry, probably an esp32 and some mosfets
order of operation:
to make water
1. close normally open permeate solenoid
2. open feed water electric ball valve
3. wait for valve to open
4. open membrane flush solenoid for n seconds
5. close membrane flush solenoid
6. open product-to-drain bypass for n seconds (to eliminate TDS creep)
7. close product-to-drain bypass
8. open permeate solenoid
... making water ...
normal shut down
1. close product solenoid
2. close feed water electric ball valve
3. open membrane flush solenoid to bleed pressure
4. close membrane flush solenoid
5. open product-to-drain bypass to bleed pressure
6. close product-to-drain bypass
... shut down ...
there's a product out there that does something similar already
Shop Ro Buddie at Bulk Reef Supply where we make reefing fun and easy.
www.bulkreefsupply.com
To make this work I need an electric ball valve 1/4npt-1/4 push connect fittings, a n/o solenoid and the pressure switches, I think I have everything else.
I've got 2 1/4 aquatec 8800 pumps just sitting around because I switched to 3/8 8800 pumps, I took one apart and cleaned it out. Going to use that to boost the feed water pressure to 80psi.