RO DI procedure, best and easiest?

I am setting up a new tank and am trying to setup my water making process to be as efficient and easy as possible.

Currently i have a buck eye field suppply RO-DI unit.

My water making process is:

Turn on the water and let it drain through RO until i get 4tds which takes 5 to 10 minutes. Then i let water go through DI and get my 0tds water. I dont use the flush valve. Should i use flush valve prior to letting the water drain through RO? And can i just go straight to getting DI water if i use flush valve.

I have heard of automatic flush valves. So I am interested in getting it for my next setup. It would be great if i can just turn the water on and have it go straight through RO and DI without having to do anything else.

Any help would be appreciated

 

You can have it going through both RO and DI membranes. What kind of setup do you have? Name and model if you can. I'm not understanding how you're "Draining" the water through it. I have my RO unit connected to the water supply line under the sink with a T and from there it goes through my filter chamber, then the carbon and then the RO membrane. I don't have DI membrane, but if I did it would go through the DI after all the other mentioned steps. And it kind of moves through it with the pressure from the water line... that's why I don't understand when you say "drain"
More than likely, AZDesertRat will be able to help you more on this. He's got this covered hands down.

- Mag.

 

+1 magnus. Put a check valve in the inlet line and cut off valves in the supply lines. This keeps the RO membrane under pressure. Like Magnus said run it through all stages. From the way you stated it, you run throu the RO unit into a tub then pump it throu the DI unit.

 

Flush valves have no proven or documented value. They are more of a feel good or warm and fuzzy thing making you think you have done something.

What you are doing is good and will extend the life of your DI resin since you are flushing the initial TDS creep water to waste via the DI bypass so it does not exhaust the resin.

There really is little advantage to keeping the system under presure other than it reduces the possibility of contamination from outside sources. If you don't have a autoshutoff valve(ASOV) I would not go through all the check valves and ball valves just to keep it wet, as long as you use it every 10-14 days it should stay wet anyway.

If you want to automate the process a bit, add an ASOV and float valve or float switches and a solenoid then plumb the feed water and drain in permanently. Get a storage container like a Rubbermaid Brute or old aquarium and fill it based on level. The disadvantage is you may not be there to flush the TDS creep as you have been doing but it won't make a huge difference in the life of the DI. The advantage is you don't have to babysit the water making process.

 

Thanks, thats exactly the info i needed. I will set up a 50g holding tank that i will keep filled. I def don't want to babysit the process anymore. Question is will i get better water if i manually turn it on until 50gallons fills and float switch turns it off? Then turn it off until my 50g tank is empty. Then the creep water will have minimal effect on such a large amount of water.

Or if i just keep it filled as you say? Are both ways equally efficient? and the latter just easier?

 

The final RO/DI water should be the same either way if you have a good DI filter. If you made it manually you would see a slight increase in DI resin life since you could flush the TDS creep out but is it worth your time? Probably not.
A solenoid valve and float switches helps since you can adjust the level so it has to drop XX number of gallons before it starts up again versus a float valve that drops a minimal amount before it starts over again. Personally I use float switches and a solenoid valve and get over 1000 gallons per DI cartridge. The savings in DI replacements pays for the hardware.

 

K, i will do the same thing as you. Any recommendations on a particular solenoid?

 

Here's the solenoid valve I got. The link and picture should be in the post. Good luck.

 

I use the 1/4" version found here:
Solenoid Valve Controller by SpectraPure
It includes high quality high and low float switches, a solenoid and a DC power supply so its safer than 120v AC.

Here is a photo of the float switches installed in my 23 gallon Rubbermaid recycling can. The level must drop 11 gallons before the bottom switch allows the RO/DI to start again so TDS creep is minimized and diluted.

 

Minimized and diluted. That's a good thing.