RO/DI Maintenance...

[texhorns98]

Outside of keeping any eye on the TDS meter, eventually changing membrane, etc. What else does one need to do to maintain the RO//DI unit? I hear of flushing membranes, etc. But I've never done it before.

 

[texhorns98]

I just realized I never got a reply on this question. Anyone?

 

[skriz]

I backflush my unit every so often. Other than that, I change the prefilters. Nothing more to it.

You could add a dab of bleach and run it through the unit, but it's not necessary.

 

[texhorns98]

Skriz;349609 wrote: I backflush my unit every so often. Other than that, I change the prefilters. Nothing more to it.

You could add a dab of bleach and run it through the unit, but it's not necessary.

How does one back flush the unit?

 

[bclark7169]

mine has a backflush valve on it and you just turn the valve and turn it on and water only comes out the waste side

 

[texhorns98]

Hmmm...any purewaterclub users out there know if they have backflush valves? I'll have to inspect when I get home!

 

[texhorns98]

ares;349765 wrote: it should be on the waste water line... if it has one

Wouldn't you have to close off the valve to your good water line as well? I would check my "instructions" but they are garbage!

 

[dv3]

pm onedummhikk with a link to the thread...id like to know too

 

[james s_]

Here ya go...watch the video and it explains everything......

 

[one dumm hikk]

dv3;349908 wrote: pm onedummhikk with a link to the thread...id like to know too

Like to know what? RO/DI maintenance or how the bypass setup works?

Remind me to teach you how to send a PM though

 

[dv3]

i was wondering if a back flush is done and if it is nessecary? ....also what if you put shut off valves before and after the the membranes to keep it under pressure ...would that preserve the membrane longer?


...lol i know how to pm for some reason i always use the vistor message on here

 

[one dumm hikk]

dv3;351121 wrote: i was wondering if a back flush is done and if it is nessecary?

Can an RO/DI system exist and operate properly without being flushed? Yes. The difference is in membrane lifespan.
If you watch the video, its shows bypassing the flow restrictor. What that does is let water run a lot faster across the RO membrane and the result is that it "washes" some of the contaminants off the RO membrane itself. Personally, I think a reverse flush works better. Just nowhere near as easy to do as the "standard" flush kit.

dv3;351121 wrote:
....also what if you put shut off valves before and after the the membranes to keep it under pressure ...would that preserve the membrane longer?

No. It won't even help stop TDS Creep. When the system is under pressure, the pressure keeps the TDS from reaching the other side of the membrane. When the pressure stops or equalizes so that you have the same pressure on both sides, Osmosis again takes over and the TDS "creeps" through the membrane to come to equilibrium. The only way you can stop TDS creep is to continously produce water or to remove the membrane and drain all the water out. Otherwise, its going to creep.

If you wanted to store it, you would keep it in a bag while damp to keep it from drying out but the pressure wouldn't make any difference.

dv3;351121 wrote: ...lol i know how to pm for some reason i always use the vistor message on here

Uhh, yeah, ok

 

[dv3]

James S.;349910 wrote: Here ya go...watch the video and it explains everything......http://www.bulkreefsupply.com/RO/DI-Filters-&-Systems-RO/DI-Accessories/c9_11/p519/Flush-Kit/product_info.html">http://www.bulkreefsupply.com/RO/DI-Filters-&-Systems-RO/DI-Accessories/c9_11/p519/Flush-Kit/product_info.html</a>[/QUOTE]
good link ...now i know what it is ....looks east to make

[QUOTE=][B]ares;349614 wrote:[/B] mine has a flush valve, supposed to clear the RO membrane of debris and improve efficiency and life, but Im told its all or nothing, if you dont clear it for about 5 minutes before every use, may as well never do it. no clue if its true, but I read it on the internet so it must be! I dont ussually bother with it :/[/QUOTE]
is this true?

[QUOTE=][B]One Dumm Hikk;351340 wrote:[/B] Personally, I think a reverse flush works better. Just nowhere near as easy to do as the "standard" flush kit.[/QUOTE]
how does a reverse flush work?

 

[oldschool52]

I've read and or heard if you run your RO regularly membranes last longer. Don't know if this is true or not. I run my just about daily since I only produce 5 gallons at a time. I have an auto shut-off on the 5 gal bucket lid. Works great and no more water on floor if I forget to turn off unit. Check my TDS every other day or so, reads 0 if the RO water has been dipped into a few times it has gone as high as 7 TDS. My tap water is about 51 TDS and the water I used from Publix before RO was 21 TDS. Problem I have is the pH of the tap or RO water is 6.0 so have to buffer before adding to tank. About 1 tsp of sodium bicarb / gallon to bring it up to 8.2 (ph of freshwater checked with freshwater test kit, I have both high and low pH kit for freshwater)

 

[one dumm hikk]

dv3;351401 wrote: is this true?
how does a reverse flush work?

The more you flush it the better but its not truly an always/never proposition. Once a month is better than not at all but once a week is even better. If you get in the habit of doing it each time you make water, it becomes routine and you don't even realize you are flushing it.

Reverse flush. Take a second RO membrane housing and plumb it backwards with a booster pump on the "pure" outlet. Then you close off the original inlet, and the water goes backwards through the membrane and out the drain. Its not really worth it unless you already have everything or going to use the pump somewhere else. If you buy a pump just to do reverse flushes with, its not cost effective with the cost of the pump, the cost of membranes, and the extra life you get out of the membrane as compared to not doing a reverse flush.

I looked into the reverse flush when I was looking at ways to try to cut down on waste water in a setup that was projected to use close to 90K gallons of tap water a month.

The plan is to run the water through RO/DI, then store the waste water and use a booster pump to run the waste water back through the system again. With repeated use like that, the reverse flush becomes a friend/ally.