Automatic RODI Flushing

[phatduckk]

Hi folks...

I'm putting some thought into how I want to setup the ATO situation for my new build. My ATO reservoir is 15g and I anticipate that needing to be refilled more often than I'd like (being lazy).
With that said I thought I'd try to find a simple way to automate refilling the ATO reservoir... all in that's pretty easy with the Apex and some high/low optical sensors, solenoid valves and float valve.

My plan is to run the ATO down to my low level mark & have that trigger a refill to my max level. Easy enough... but I'm wondering if I can try and figure out how to flush the membrane for a few minutes before collecting product water to avoid TDS creep. I really am not well versed in RODI units and could use some help figuring out how I'd do that?

I'm assuming I can put a solenoid somewhere... but dunno where the correct spot is. I have guesses LOL but being pretty ignorant I don't trust my guesswork.

Here's a diagram of my unit. Any RODI experts have any advise here?

 

[NanoCrazed]

Get an autoflush valve from BRS... or any RODI company... or Amazon. . There's a video tutorial on the page below as well.

Auto Flush Flow Restrictor

Choose the Aquatec Auto Flush Flow Retrictor that meets your RODI systems flow rate. 300 mL/min 400 mL/min 500 mL/min for 75 GPD single membranes or 150 GPD Water Saver Systems 600 mL/min 700 mL/min 800 mL/min for 100 & 150 GPD single membranes or 200 GPD Water Saver Systems The Aquatec...

www.bulkreefsupply.com

 

[Qwiv]

If you want to do what you are intending, you can plumb in any 1/4" solenoid valve where the one linked above would go and control it via the Apex. Solenoid goes where the shut-off is in the picture below. That particular one linked is designed to work with the booster pump, so you are paying the added cost for them to terminate it to their connectors.

The valve just gets installed parallel to the flow restrictor allowing water to bypass it, so a good quality generic will do the same thing and you can control via apex vs the booster pump. If you already have the booster pump, the one linked above is plug/play.

It is overkill if you are filling a 15gal ATO from top to bottom, unless you are the type that actually manually flushes for every salt batch, etc. The act of filling the ATO container all the way vs just topping it off all the time with a cup water over and over pretty much resolves the TDS creep 95% with less complexity.

Make sure you include a non-apex back-up as endless water into you house reliant on Apex is a 100% no no.

 

[phatduckk]

OK cool - thanks folks. Sounds like I might not need it if I make sure to fill "a lot" as opposed to constantly filling a tiny bit (which was my plan).

I've seen the Auto Flush item before but for some reason I felt having more explicate control would be "better".

thanks!

 

[JVU]

Regarding the first part- having a system to automatically refill your ATO container- I use and recommend the Tunze Water Controller-

RO Water Controller

Make RO Water production more convenient with Tunze's automated RO Water Controller! The Tunze RO Water Controller 8555 is used to regulate the water level in your fresh water storage container. It uses two float switches to control an electronic valve. When the water level drops below the...

www.bulkreefsupply.com

I use a 5g bucket for ATO water, have it set to fill when it gets down to about 0.5g and stop at about 4g (so it isn’t creeping). Using the sensors plus an old school float valve for redundancy.

 

[phatduckk]

Regarding the first part- having a system to automatically refill your ATO container- I use and recommend the Tunze Water Controller-

RO Water Controller

Make RO Water production more convenient with Tunze's automated RO Water Controller! The Tunze RO Water Controller 8555 is used to regulate the water level in your fresh water storage container. It uses two float switches to control an electronic valve. When the water level drops below the...

www.bulkreefsupply.com

I use a 5g bucket for ATO water, have it set to fill when it gets down to about 0.5g and stop at about 4g (so it isn’t creeping). Using the sensors plus an old school float valve for redundancy.

I watched that video a while back too. Seems like I can achieve the same with Neptune gear I already have.

I guess in the end I need to understand what TDS creep actually "does". My current understanding is that it uses more of your DI resin... and from the comments above it sounds like if I fill a "decent amount" at a time (5-10g) then the "extra" depletion of the DI resin isn't so damaging - and the real "harm" is caused when you fill a small amount over & over again. Is that right?

oh.. and "harm" in the above means "depletes DI resin more than you'd want"

 

[Qwiv]

TDS Creep - you Basically got it.

I would still recommend not controlling the ATO fill with the Apex and using the Tunze linked above to the Latched Relay I linked in the other thread. Reason is you absolutely need redundancy on a open supply line of water, which means one system needs to be off Apex. The manual float is technically a back-up but a pretty bad one. The reason I suggested the main control be off apex control is pretty important. 1 - you can't edit the code and mess it up with a typo one day and 2 - having the Apex as the secondary back-up control means you get an alarm when the primary control fails. You don't get the failure alarm when you use the Apex for the primary control and that is where the value of the Apex is - the monitoring and alarms. Yes, you could add a 3rd float on Apex for alarm, but that does not cover you on an Apex fail.

 

[rygh]

Opinion:
Yes, TDS creep is what you mention.
It is really only a significant problem if you tie your RO directly to the tank, such that it goes on/off all the time, for very short periods.
If you fill a 50G Brute, maybe once a week, it is basically a non-issue.

+1 on a flaot valve as a backup. I have one, and my RO tank is outside.