How to Install an Automatic shut-off Valve (aso asv) for your RO | Stop TDS Creep 

Value?

Thank You ParatyShow!

Made my water loads better! Thanks Key!

I'm surprised nobody mentioned this sooner, but without the permeate pump, your brine line after flow restrictor simply goes to the drain, there is absolutely nothing there to keep any pressure on the brine side of the membrane after the SOV activates. Once the water supply shuts off into the membrane by SOV the brine side pressure always drops to 0. This isn't the case with the permeate pump in place, it keeps a good amount of pressure on the brine side after SOV triggers because there is a spring it charges up while its pulling permeate water. If you can relieve the brine side pressure after each cycle via say solenoid valve on short 5 second timer that bypasses the flow restrictor & permeate pump to the drain it would be like before without the permeate pump in place where the RO membrane rests with no pressure on the brine side. In my case this valve is also used to periodically flush the membrane because it does bypass the flow restriction, takes care of two issues with one solenoid. Try it, check the water pressure after each cycle that still remains on your brine line, it certainly explains a lot of the creepage when the system is 'off'.

Since I wrote that I actually took it a bit further and added an automatic permeate flush set to activate on a timer, rather than flushing the membrane with filtered water it now utilizes the stored tank water diverted into the inlet via additional solenoid. In all there are now 3 solenoids, line in from main sediment carbon, RO flush (bypasses flow restrictor & permeate pump to feed into brine drain), and the permeate flush. A few additional one-way's to prevent any possible backflow and now those membranes should last much longer so long as I remember to change the carbon blocks on time. Now I'm going to have to do a YT video on it aren't i? Inspirational ideas here.

Is nobody remembering rule 101 of semipermeable membranes..... solutes don't migrate across the Membrane by Osmotic pressure or Pump pressure, theoretically, ONLY WATER can migrate accross the semi permeable membrane (in reality a very small amount of solute may find a way but it's a small, almost negligible amount). So now when the tap is turned off the low PPM dissolved solids side gives up its water to the high ppm side. As the high ppm and also high pressure side side drains out the waste side water continues to migrate from the good low ppm side until an equalization occurs....a 1 way check valve on the low ppm low pressure side prevents drawing good cleaned water all back accross the semi permeable Membrane if raw water pressure is lowered. You have 2 gradients at work...... the semi permeable Membrane trying to work on osmotic pressure and the same Membrane being forced to filter against that initial gradient in a pressure gradient by the higher raw water inlet pressure. It will just fluctuate based on which is creating a higher pressure at the time.....be it modified by the flow restrictor, one-way check valve, or the auto shut-off valve. Make sense?

whats the ppm in your water supply?

​@@RPDBYshould be 500-700 ppm if gets 7 from just the membrane. The DI resin, i wouldnt reccomend for drinking water. 😂. As for the aquarium storage he uses non pressurised tank wich makes the membrane soo efficient. But in a kitchen setup with the pressurised tank you will not get just 7 ppm from 700.

Actually I was swamped working on a rental house. Were are starting to film the bunker repairs now, stay tuned!

Tim, that's terrible! 700 tastes like I'm drinking a battery

@@HerbOMatic I bet. I'm in Buckeye. 10 years ago we were pushing 2,000. The city replaced some pipes and we're now around 1,400. Our RO brings it down to sub 200. Fine for cooking, but I still get bottled water for drinking.

@@HerbOMatic 2022 phx sample report shows 570-764 TDS which is in line with the testing results I've seen from phx locations as someone who works with water professionally.

The water, called brine, instead of it going down the drain, it goes to the pump and runs the pump. The pump takes the RO water, and forces it into the tank at a higher pressure then without the pump. Hence saving water as the tank fills faster, just from using the brine water to make that pump push the RO water into that tank without as much back pressure, which would cause a slower tank fill, and much more water down the drain. There's a couple good videos on RU-vid that show you the time, and water savings with, and without the pump. I just went and found it, they explain and show real world results using the pump that runs on waste water. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-RT89QxN1FIA.html

The pressure would be extremely low, as it was for mine without the storage tank.

In Australia our tap water is never over 200ppm out of the tap in a modern house build. I only have a RODI system because I need 0 TDS water for my reef aquarium.

Some dissovled solids will always get thru. Otherwise you should get 0 PPM water.

Membranes have different ratings 96%-97% are pretty common. Say you're starting with 300 ppm tds tap water, a 97% membrane will output around 9 ppm tds. If you're using a super low yield membrane like a 25 or 35 gpd you can get a 99% rejection rate. So starting with say a 50 ppm tds tap water and a 99% membrane you would end up will under 1 ppm tds. To eliminate that last 5% you typically would use a mixed bed DI resin cartridge.

@TofuInc thank you for un-confusing me appreciate the knowledge 🙏

Did you replace it with another one?

@@a.draghici8956Yes, I returned the ERP-500 to the seller and he replaced it with an ERP-1000 that has been working well with no issues.