• Welcome back Guest!

    MARSH is a private reefing group. Comments and suggestions are encouraged, but please keep them positive and constructive. Negative threads, posts, or attacks will be removed from view and reviewed by the staff. Continually disruptive, argumentative, or flagrant rule breakers may be suspended or banned.

Any Pasadenians with RO/DI unit? (1 Viewer)

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)
C

Cakepro

Guest
Joined
Mar 25, 2003
Messages
1,093
Reaction score
0
Location
Houston
I (prematurely) replaced my RO membrane a few months ago with a Dow Filmtec 75 GPD membrane and have had problems with the output of my unit. At first it was phenomenal, and it has slowly withered down to a trickle, although my media have all been replaced. I have checked all of my lines...all clear. The last thing to check was the membrane itself and I discovered that it has crystals all over it. They look like kosher salt crystals in size, color, and texture. Do any other Pasadena water users with an RO membrane have this problem? If not, I am taking this problem back to the source from which I bought my new membrane.

BTW, I had my RO unit for three years without any crystalline buildup. I also have a dial-in waste water adapter and have it dialed in to 1:4. Actually, it's slightly more than 4 gallons wastewater to 1 gallon RO. TDS out of the membrane itself is 10 PPM, and the tap water is 170 PPM. Anybody know what is the usual RO rejection rate of TDS?

BTW, I am not using DI right now as I am awaiting replacement DI resin. All of these problems are present both while bypassing the DI and post-DI, and I suspect my DI resin burned up prematurely because of this problem.

Thanks,
Sherri
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
Sherri,

Do you flush your membrane out from time to time? I usually flush mine once a week for about 15 minutes or so and have never had any problems with it. My water TDS is about 350 or so from the tap.

Brandon
 
J

jawsk2

Guest
Joined
Apr 15, 2003
Messages
71
Reaction score
0
Location
Clear Lake
I live in Clear Lake, and we get our water from City of Houston, which I'd guess is where you get yours. I also flush the membrane and it takes a year or so before the flow slows that dramatically.
Or, maybe they did some work on the lines and a big clump of crap made it through the line??
 
G

Guest

Sherri

I have not seen any problems in DP, water supply might be different
than yours.
I just pulled 20 gallons today. Everything looks good.

Robert
 
C

cparka23

Guest
Joined
Aug 2, 2004
Messages
714
Reaction score
0
Location
Memorial
Don't you have to soak and rinse out/flush the membrane before you run it? Perhaps you're seeing dust particles clogging output? I'm not an expert but think that that was mentioned somewhere on the BuckeyeFieldSupply FAQ thread. I could be (read: probably am) wrong.
 
OP
OP
C

Cakepro

Guest
Joined
Mar 25, 2003
Messages
1,093
Reaction score
0
Location
Houston
The city of Pasadena has its own water supply, as far as I know. The TDS between my water and my mom's (which is the city of Houston) is quite different, and she only lives about 15 minutes away from me. I flush for 15 seconds to 30 seconds (15 seconds is the recommended time per Kent Marine).

I flush the membrane every time I use the unit, which is about every 10 days or so to fill a 55 gallon drum.

There's no way anything larger than .6 microns could filter its way through the unit, as the sediment filter is the first in line.

Show me the numbers, baby. Don't tell me it "looks good" without those all-important numbers. Hehe ;)

~ Sherri
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
I replaced all my filters a few months ago and my TDS after RO/DI is at 3 ppm. I use the RO/DI unit from Global. I make about 40 gallons of water or so a week sometimes more depending on how motivated I am to do maintenance.

Brandon
 
K

KarenB

How does one flush out their RO/DI unit? Do you just run the water in reverse?
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
Karen,

you just flush the RO membrane every once in a while to remove any buildup on the membrane. it prolongs the life of it. All you do is bypass the flow restrictor which causes a rush of water to flow across the membrane dislodging any particulate matter.

Brandon
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
lol it will be on the waste output line of the RO/DI unit...it slows the flow of water down so water is forced through the RO membrane and out the permeate output line :)

Brandon
 
K

KarenB

Okay.......I've familiarized myself again with the unit. I have obviously been bad, since I've never flushed it out. Just figured I'd change the gizmos in the dealies whenever they needed it. I had so much fun setting it up, that when I finally got it to work, I left it alone, LOL.

So then I need another piece of tubing to run directly past the flow restrictor, and then what? Where does the particulate matter go then? Seems it has nowhere to go if it's blocked by the membrane. Maybe I'm just ignorant.......okay, well, I am ignorant. More details, please :D
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
Here is a picture of the flow restrictor/flush kit that BuckeyeFieldSupply sells

Product_65.jpg


how is works is when you open the valve on top the water bypasses the flow restrictor (bottom valve) which causes almost all the water to flow through the RO membrane housing and out the waste water line. The film/particulate matter that is built up on the membrane is then washed out the waste line. Your RO/DI unit my have a different type of flush valve/flow restrictor. If you want to flush the membrane you could also disconnect the flow restrictor on the unit and let the water flow out if there isn't a flush valve.

Brandon
 
K

KarenB

Okay.......so I disconnected the line BEFORE the restrictor and just ran water through it like that. Is that right? I noticed no water came out any other place. I did this for like half a minute. I didn't see anything coming out except water, no solids or anything. Note: I haven't had any problems with my output in the past.
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
yeah unless there is some other form of valve upstream of the restrictor :) when you disconnected the line the permeate water output should have been very very little or none. The solids and what not that build up on the membrane are going to be extremely hard to see since it goes through all the other cartridges before it hits the RO/DI membrane. Most buildup is just going to be a slimy film if I remember correctly.

Brandon
 
K

KarenB

You're using terms I'm not familiar with......permeate something or other. Is that the final product water you're talking about there? If so, then no, I had very little, if any, water coming out of there when I flushed, if I did flush it, LOL.
 
A

AggieBrandon

Guest
Joined
May 22, 2003
Messages
2,045
Reaction score
0
Location
Bellville, Texas
yeah I think that is what it is called permeate water = good water :) bad water = waste water :) I think you did a good job flushing your RO/DI unit then :) class is dismissed :)

BNH

how's that for smiley's
 
K

KarenB

Yay, I passed, then.........that was easy, sort of, LOL. Thanks, Brandon!!

Loved the smilies, btw :D
 
You must log in or register to reply here.
Top