4 stage rodi

[jdpeters]

Just coming back to the hobby after a 4+ year hiatus. My 4 stage has been sitting for over that long so I decided to just change out all of the stages today including the RO membrane. My question is should I leave the cartridges empty and just run the RO membrane for one hour to flush the new membrane or should I run all of them with the new cartridges in?

 

[t5Nitro]

I would flush the pre membrane stages just to clear carbon dust. If you can, you can flush the premembranes and send RO input line to the drain to avoid sending all the dust to the membrane. Maybe make 2-5 gallons worth.

Then, you could connect the line to the membrane and flush that for another few gallons or so.

See what others think on the volume of water to make to flush, but I'd recommend flushing the pre membrane stages on their own before flooding the membrane with the dust.

 

[andrewey]

I was typing it out, but @t5Nitro nailed it. I probably don't make as much as 2-5 gallons when flushing carbon (whether this is right or wrong, I'm not sure), but I rinse all my stages and the RO sequentially with the waste going down the drain and not to the next stage.

 

[B&CinB.C.]

I've read that if you flush a new membrane through your di resin there's a preservative on the membrane that will kill your di resin quickly

 

[jdpeters]

I would flush the pre membrane stages just to clear carbon dust. If you can, you can flush the premembranes and send RO input line to the drain to avoid sending all the dust to the membrane. Maybe make 2-5 gallons worth.

Then, you could connect the line to the membrane and flush that for another few gallons or so.

See what others think on the volume of water to make to flush, but I'd recommend flushing the pre membrane stages on their own before flooding the membrane with the dust.

Is the RO membrane the last stage then? I never thought about that before. I’m so happy to slow down this time and learn so many things I missed on my first two systems.

 

[jdpeters]

I've read that if you flush a new membrane through your di resin there's a preservative on the membrane that will kill your di resin quickly

This was part of my confusion

I was typing it out, but @t5Nitro nailed it. I probably don't make as much as 2-5 gallons when flushing carbon (whether this is right or wrong, I'm not sure), but I rinse all my stages and the RO sequentially with the waste going down the drain and not to the next stage.

Thank you for responding also!

 

[t5Nitro]

I was typing it out, but @t5Nitro nailed it. I probably don't make as much as 2-5 gallons when flushing carbon (whether this is right or wrong, I'm not sure), but I rinse all my stages and the RO sequentially with the waste going down the drain and not to the next stage.

Thanks, it seemed like a lot to me after I wrote it out, especially for the carbon flush. Sometimes the membranes, if I remember, are recommended to waste at least a few gallons. The carbon flush is probably much quicker than that.

Is the RO membrane the last stage then? I never thought about that before. I’m so happy to slow down this time and learn so many things I missed on my first two systems.

This should be your last stage before a DI resin cartridge/s. You don't need to flush resin.

 

[jdpeters]

I was typing it out, but @t5Nitro nailed it. I probably don't make as much as 2-5 gallons when flushing carbon (whether this is right or wrong, I'm not sure), but I rinse all my stages and the RO sequentially with the waste going down the drain and not to the next stage.

I thought I understood but now I’m lost. Should I put the Ro membrane, sediment filter and carbon block in and then run it for 2-5 gallons THEN add the di resin and I’m good to go?

 

[JumboShrimp]

Maybe some kind soul here with experience could say, do this:

Step 1
Step 2
Step 3 (etc.)

 

[t5Nitro]

Step 1: connect water supply line to the prefilters (stages 1-3 for you) and then run the those into the drain. Make a few gallons to waste.*

Step 2: connect prefilters to the RO membrane now rather than to the waste. Make another couple of gallons to flush the RO membrane.**

Step 3: connect the RO membrane now to DI resin. So your final sequence is prefilters to RO to DI resin to ATO storage container.


*The first step just prevents sending carbon dust or other sediment into the RO membrane right from the start.

**I would flush the membrane this way rather than by itself because you now have flushed pre filters to send somewhat filtered water to the membrane. Don’t send tap water to the new RO membrane since itll have to work a lot harder to filter all the TDS.

 

[B&CinB.C.]

I have an Aqua fx Barracuda 4 stage system . If you google aqua fx filter change instructions they have a video that covers this

 

[andrewey]

The only step I do differently from @t5Nitro is if I have two carbon blocks in a row (which I run), I run the system with only sediment filter (stage 1) and 1st carbon block (stage 2) in place. My third stage is empty when I pass water through the first two stages. I then add the second carbon block (stage 3).

My rationale is to reduce how many carbon fines go to my second carbon block. Think of this as step 1A and 1B. Almost certainly overkill in practice, but only adds 5 minutes to the process, so I've continued this "ritual". The current instructions are probably the more reasonable and realistic approach.

The rest of the approach is the same.

 

[jdpeters]

Step 1: connect water supply line to the prefilters (stages 1-3 for you) and then run the those into the drain. Make a few gallons to waste.*

Step 2: connect prefilters to the RO membrane now rather than to the waste. Make another couple of gallons to flush the RO membrane.**

Step 3: connect the RO membrane now to DI resin. So your final sequence is prefilters to RO toDI resin to ATO storage container.


*The first step just prevents sending carbon dust or other sediment into the RO membrane right from the start.

**I would flush the membrane this way rather than by itself because you now have flushed pre filters to send somewhat filtered water to the membrane. Don’t send tap water to the new RO membrane since itll have to work a lot harder to filter all the TDS.

Ok this makes perfect sense, thank you for your time!

 

[jdpeters]

I have an Aqua fx Barracuda 4 stage system . If you google aqua fx filter change instructions they have a video that covers this

Thank you I will check that for reference

 

[t5Nitro]

You'll probably find a number of ways people will slice this cake. All of them are likely reasonable. The punchline is to pick a method that sounds reasonable to you with maybe the goal of improving filter longevity.

 

[jdpeters]

You'll probably find a number of ways people will slice this cake. All of them are likely reasonable. The punchline is to pick a method that sounds reasonable to you with maybe the goal of improving filter longevity.

I got the RO membrane On now after the intial flush and it got down to 0 tds within about 30 minutes, would you say I could add the di now? My source water is only 65~ TDS we have pretty clean water