RO/DI ... what am I doing wrong?

[JohnnyAirtime]

Okay...
I'm a bit perplexed.

I bought a used RO unit from a reefer, who told me the filters/membrane should be replaced. So, I first installed the unit, and it seemed his lines were a bit connected incorrectly (I watched the Bulk Reef Supply videos numerous times one night) so I fixed that. See, he also had a DI canister, and another for activated carbon that he used post RO system.

When I first ran the system, I let it run for 20gallons. And got about 380 TDS IN... and 200s post everything. So I ordered new filters AND membranes... see, he had a second RO membrane to collect waste water and send it through again. Making a 75gpd system, a 150 (so BRS web says).

Here's how it's currently plumbed;

1. (TDS METER 1: IN)
2. .5 Micron sediment
3. .1 Carbon Block
4. RO Membrane 1
5. (TDS METER 1: OUT)
6. Waste water into RO Membrane 2
   ... both membranes out to;
7. (TDS METER 2: IN)
8. Activated Carbon Canister
9. Chloramine Canister
10. DI Resin Canister
11. (TDS METER 2: OUT)

EDIT; Found initial problem from original post, and corrected my comments.

BUT....

TDS1-IN: 380
TDS1-OUT: 18
TDS2-IN: 16
TDS2-OUT: 98

How can it go up, after going through a;
Activated Carbon, Chloramine filter, and then the DI Resin?

... is the activated carbon injecting TDS?

Maybe I should delete the activated carbon post RO (since I have a carbon block pre RO), and add a second DI resin Canister? THOUGHTS????

 

[Gtt1988]

hmm does your membrane have the rubber ring(gasket) on it. and if so is it in good condition bc your water may be missing your membrane and not running through the membrane. whatever it is, it has to do with your membrane not your sediment nor carbon block.

 

[JohnnyAirtime]

hmm does your membrane have the rubber ring(gasket) on it. and if so is it in good condition bc your water may be missing your membrane and not running through the membrane. whatever it is, it has to do with your membrane not your sediment nor carbon block.

Ya, I found "part" of the original problem I posted about (and have since edited my post to reflect it)... but, the original issue was one of my membrane WASTE lines was connected as a "good" water. I simply swapped it, and all got LOTS better.

... however, now... I need to know why my TDS went up after my RO system. (see new comments).

 

[JohnnyAirtime]

...............

Here's how it's currently plumbed;

1. 
   ... (TDS METER 1: IN)
2. .5 Micron sediment
3. .1 Carbon Block
4. RO Membrane 1
   ... (TDS METER 1: OUT)
5. Waste water into RO Membrane 2
   both membranes out to;
   ... (TDS METER 2: IN)
6. Activated Carbon Canister
7. Chloramine Canister
8. DI Resin Canister
   ... (TDS METER 2: OUT)

TDS1-IN: 380
TDS1-OUT: 18
TDS2-IN: 16
TDS2-OUT: 98

.........

With the above, I moved some items around so I could see different info from the RO System. However, I noticed the RO System first membrane output reads 11 and the second membrane (that is using reclaim water from the first membrane) output reads 16. So that confirms the second output is trying to push dirty waste water and get a decent output result. Being the waste water from membrane 1 is probably above 400PPM, that's not too bad of a reading.

So, what happens is the 11PPM and 16PPM water combine and go to the Activated Carbon, Chloramine filter and final DI Resin.
EDIT: It's now down to 7PPM and 8PPM

I'm going to change this around one more time, so that the final output for drinking water is AFTER the Chloramine filter (instead of after RO system) and the RO/DI water for reef use will be AFTER the DI Canister.

... and, I'll add one more DI Canister. For a final config of (a 9 stage RO/DI system);

1. 
   ... (TDS METER 1: IN)
2. .5 Micron sediment
3. .1 Carbon Block
4. RO Membrane 1
   ... (TDS METER 1: OUT) "tests water only out of membrane 1"
5. Waste water into RO Membrane 2
   ... (TDS METER 2: IN) "tests water only out of membrane 2"
   
   Both membranes out to;
6. Activated Carbon Canister
7. Chloramine Canister
   ... T Off for drinking water
8. DI Resin Canister 1
9. DI Resin Canister 2
   ... (TDS METER 2: OUT)
   ... Output for RO/DI to container

I know it's a bit of overkill on the DI, but... should perform exceptionally well. WHAT'CHA THINK??? ...come on, someone has to have some input!

 

[shifty51008]

ok here is what i see is wrong.

the carbon and chloramine filters need to be before the membranes as these are prefilters and having them after the membrane will add TDS to your water that you just cleaned.

next, because you are running 2 membranes you need to check what the water pressure is going into each membrane, you want at least 60psi for each. most household water pressure will be fine for 1 membrane but usually can't get enough for 2. most people use a booster pump in order to get the pressure up to the 2nd membrane.

here is the order I would run the filters.
5 Micron sediment
Carbon Block
Chloramine Canister
RO mebrane 1
RO membrane 2
DI
DI

and you can get rid of the Activated Carbon Canister unless you want it for taste for drinking water add a bypass for RO water and then have it go to your RO water only but don't let it run through the water before the DI.

hope this helps

 

[jeff@zina.com]

In addition to what Shifty says, dump the second DI unit. It doesn't do a thing besides double the amount of resin. Water passing the first DI should be at TDS of 0, whether or not anything else is working. Change your DI resin.

Also, no instructions on this from the manufacturer/seller? Kind of a crappy unit in that regard.

Jeff

 

[disc1]

Definitely put the carbon blocks in front of the RO. They will add TDS.

 

[JohnnyAirtime]

Sounds good fellas...

I'll change it so that it passes through activated Carbon, and chloramine filters before RO membranes. ...dump out to drinking water, and then pass it to final DI resin.
(Just to clarify, I do have "activated carbon" AND "carbon block" in this unit. Yes, I love my drinking water!)

I do have 80psi in from tap, and 70psi at the first membrane.
... I'll verify pressure at the second membrane, but I also do have a CDP-8800 booster pump. So, I do know about the pressure needed for osmosis to work.

(Jeff) And instructions? bought it used, and upgraded it. If you READ the first post, you'll see I mention that.

Here's how I'll late it out;
.5 micron sediment filter
.1 micron Carbon Block
Chloramine Canister
Activated Carbon
RO mebrane 1
RO membrane 2
DI
DI #2 optional (if it's at zero from first DI, then resin will last longer)

Thanks for all your help!

 

[disc1]

I would put the 0.1 um Carbon block the last thing before the RO.

Like this:
Sediment
Activated Carbon
Chloramine (This one really isn't needed unless you have really bad tap water)
Carbon Block
Ro
DI

 

[JohnnyAirtime]

Great idea DISC.
(however, due to the canisters... I had to improve a bit)

I'm currently running;

380PPM in from tap
.5 micron sediment filter canister
chloramine filter canister
activated carbon canister
.1 micron carbon block
RO mebrane 1
008PPM
RO membrane 2
003PPM
... drinking water T-Valve here
DI
... output valve to storage container for RO/DI reef water.
000PPM

I had to make some big changes... due to the used RO system being plumbed backwards through the two canisters. I JUST noticed tonight, that it was reversed. Now, it's flowing 100% correct, I have 80psi in from tap and 72psi into the first membrane (no booster pump). I'll get around to checking the pressure into the second membrane when I get some time....

I'm happy with where it's at now.... so, thanks for ALL your help!!!

The DI output of 000PPM is probably due to me also changing out the DI Resin, with some new stuff. The other I had in there, was from the previous owners storage container... and it looked, "odd" to say the least. I threw it out, and will just order new as needed.

 

[JohnnyAirtime]

Gotta' love RO/DI systems!!!!

 

[shifty51008]

congrats, that is what it should be doing