RODI Ideas

[cromag27]

you can also do a simple test to determine if it's even worth it.

set up the rodi and let it run for about 15 minutes. note the post membrane tds.

then set it up automatically like you had originally wanted to do. note the post membrane tds right when it kicks on, and right when it turns off.

these figures will establish how much tds creep you have built up, and if it totally flushes from the membrane before the unit turns off.

 

[MSB123]

you can also do a simple test to determine if it's even worth it.

set up the rodi and let it run for about 15 minutes. note the post membrane tds.

then set it up automatically like you had originally wanted to do. note the post membrane tds right when it kicks on, and right when it turns off.

these figures will establish how much tds creep you have built up, and if it totally flushes from the membrane before the unit turns off.

I just am wondering if it is worth it do do the flush. I think that’s its a cool idea, but not really worth it. We will see.

 

[cromag27]

I just am wondering if it is worth it do do the flush. I think that’s its a cool idea, but not really worth it. We will see.

that's why i suggested the test. it depends on several variables including: your incoming tds, how long the unit remains turned off, the efficiency of your membrane and if you even care to do it. lol. here in arizona where our water is horrible, it's worth flushing more so than in other areas where the tap water is better.

 

[Neo Jeo]

I have a RO line ran to my tank into this unit:
https://www.avastmarine.com/products/barrel-tender

Then I have a float valve connected to solenoid if it malfunctioned. Then I have a tunze hooked up to the sump and that 5g bucket. Works well

 

[DLHDesign]

I had an Apex-run RO membrane flush valve set up. It involved 2 sensors (low/high water levels) and 3 solenoids - the first on the water input line (call that the "main valve"). The clean line out of the membrane had a "T" fitting that each led to another solenoid. One branch of that led to my DI canisters ("product valve") while the other was joined (through another "T") to the drain line ("flush valve"). Because this involved 3 solenoids (and I was already using one 24v port for a PMUP), I also had to get a 1-link module to power them all, in addition to the FMM I used for the sensors.

I no longer have the code (sorry!), but I don't recall it being overly complicated. The gist of it was that the main valve was turned on by the low-water optical switch of my ATO container and off by the high-water sensor (which were about 12" apart) - you could use the sensors in your DT/sump as well, of course. The product valve would open with the main valve, but with a 1min delay (which is a bit more than what I measured it took for my membranes to flush down to their operating levels). The flush valve would open when both the main and product valves were open, otherwise be closed. I also had a mechanical float shut-off on the product line in case something failed.

The system worked fine while I used it. I've since upgraded to a larger storage container for water production and mixing, so I don't need to make water on-demand any longer.