RO DI system question

[obarrera]

This is the first time I’ll use an ro di system and I came upon this info and would like to know if this is recommended to do for every ro di system, I’m trying to make the filters last as long as possible. It’s a 4 stage brs ro di with tds Meter, if that matters.

“ Manufacturers recommend flushing new carbon block cartridges for at least 10 minutes before using the product water. Don’t run flush water through other stages in your system.

If you are using Catalytic GAC, or CGAC to treat chloramines, it is critical that you thoroughly rinse these cartridges. They will release fine black carbon dust when first installed. Don’t run this rinse water through later filter stages.

Manufacturers recommend flushing new RO membranes for up to 40 minutes to remove preservatives before using the product water. Don’t run flush water through other stages in your system.

Run 1.5 gallons of flush water through new DI resin before using the product water. Avoid contaminating (e.g., bacteria/mold/fungus) DI resin. Minimize storage time. Store DI resin in an airtight container to keep it moist until use. Store unused DI resin in an opaque container to avoid exposure to light. Clear shipping bags are appropriate for long term storage. Treat your resin gently! If resin is exposed to freezing temperatures during shipping, allow it to warm at room temperature for 24 hours prior to use.”

[oceanslide]

Yes always flush the new filters, don’t let the water after the carbon blocks go into your ro membrane, you will see when you flush it it’s pretty dark for a second. Not sure about flushing the new di, I’ve never done that but I guess it couldn’t hurt? Anyone flush out their new di at all?

[[G]h0s'][']

Curious, How do you go about flushing g these cartridges without them going g to the other stages? How do you flush the memberane as well?

[oceanslide]

Curious, How do you go about flushing g these cartridges without them going g to the other stages? How do you flush the memberane as well?

I just disconnect the line out from the carbon blocks and put in a different piece of tubing and route that to the drain.

[Drama D]

YEP^^^ this is how I do it. I also flush membrane for 5 mins before use and after use.
One other thing I do when replacing carbon blocks and sediment filters is I disconnect the membrane, add a line to the drain from the filters. Then remove the filters. Add a few capfuls of unscented bleach to the sediment cartridge area, turn the water on and let the sediment and carbon block areas fill with water, then turn unit off and let sit for 10-15mins. I then flush these cartridges for 10-15mins and or until there is no smell of bleach. I then replace just the sediment filter, flush that for about 5 mins, then replace carbon blocks, flush for 5-10mins, reconnect membrane, flush this if just replaced, then replace di cartridges, then flush for 5g and discard that water. Then ready to make water. If just replacing di, I'll flush 5g before making water. If just sediment and carbon, I do the steps above.

[dizzyjay]

Interesting. I’ve never thought about flushing DI (other than the standard before/after use. Do you notice any off putting smell or color in the flushed DI water or measure higher tds?

[obarrera]

Awesome I’ll set it up today and hopefully do it right. I’m surprised not a lot of sellers mention about flushing, I think I saw it originally on ro buddies set up video.

Thanks I really appreciate the quick replies 👍

[Drama D]

I do notice a fishy smell with fresh di, not so much after the flush. I've flushed the first 5g of di since owning a rodi system. It was recommended back in the day on spectrapure systems. I've only ran spectrapure systems until recently and decided to upgrade/try another brand, went with the brs 7 stage pro system. Couldnt be happier, waste ratio has improved dramatically, more gpd, added carbon block for chloramines, makes water way faster, mixed bed resins. But I still use the same practices when changing filters/resins and twice a year maintence on system.

[[G]h0s'][']

Sorry to slightly hijack the thread a bit. Dan, what is your psi? I have on of those passive ro/di pumps laying around that I haven’t installed yet. My water bill has been pretty high and wonder if that pump would make a difference.

[DWILL]

There’s no need to flush the DI. If you flush the DI with tap water you’ll burn through the resin quickly.

Also, you should back flush the ro cartridge for 3 or 4 minutes before running water through it, the flush the RO out put until the TDS drops before running the RO output through the DI. Doing the first will increase the life of the RO membrane, doing the second will increase the life of your DI resin.

Also if you a BRS 4 stage unit check to see if you the universal carbon block. There is right max allowable amount of chloramine in the water in San Diego county. If you have the regular carbon block it may not remove the chloramine, it also won’t last very long. Make sure to keep a eye on your water for chloramine break through. You can test your waste water for chloramine/chlorine break through.

[goody]

I too just hooked up an rodi unit. Didn't think about flushing the cartridges. All are new except the membrane. Since I've already used some of the water, what harm can it cause tank?

[Drama D]

@ ghost, I do use a booster pump on my system set at 75 psi, standard pressure without to my system is only 40psi.
And I agree with d will as far as flushing membrane before making ro/di to make di last longer and get rid of the tds creep. A nice inline tds meter will allow you to view tds creep and know how long to flush for

[dizzyjay]

I like the idea will be adding a bypass of the ro membrane set up after the sediment filters for when i change them; basically as a way to prolong the life of the ro membrane- probably not too huge of an issue if you didn’t flush them but I could see that initial runoff getting stuck in the membrane or exhausting some of your di (guessing negligible but can’t say none) at the end of the day you want tds = 0 (and chloramines=0) regardless of how you get there. +1 for universal carbon block- (as 2nd carbon run inline) very important in SD.

[DWILL]

I like the idea will be adding a bypass of the ro membrane set up after the sediment filters for when i change them; basically as a way to prolong the life of the ro membrane- probably not too huge of an issue if you didn’t flush them but I could see that initial runoff getting stuck in the membrane or exhausting some of your di (guessing negligible but can’t say none) at the end of the day you want tds = 0 (and chloramines=0) regardless of how you get there. +1 for universal carbon block- (as 2nd carbon run inline) very important in SD.

Not flushing the membrane will reduce its life fairly significantly depending upon the TDS of the source water. Here in SD county TDS average is over 300. You can get a flush valve from BRS pretty inexpensively or you can get them on Amazon for a couple dollars less.

[Kaifish]

I use and aquatic life booster pump and it automatically flush’s the membrane before and after use. Makes it nice cause I’ll forget