RO/DI help

[.OptimusPrime.]

Was away this past weekend. Came and noticed that my top off bucket was low so I went to fill it up.

 

When I left on Friday none of the filters/di resin showed any exhaustion/use. When I came back the DI resin was pretty much 75% used up with the other 2 filiters looking like they did when I left. I didn't think anything of it. Checked the TDS in at around avg 200. TDS out was off the charts...over 400 and beyond to the point where the meter didn't register (highest I saw as 800 something).

 

Figured I need to let it run for a bit since it hadnt been used recently. I let the unit run for awhile and came back the TDS out was starting to go down to the 120's then all of a sudden creeps back up to off the chart levels.

 

About a week and a half ago everything was fine. 200 in - 0 out. and none of the filters/di resin seemed to be exhausted.

 

I did recently add the 150gph upgrade and changed to all new filters but that was a month ago and I only made maybe 30 gallons since then?

 

What gives?

[Chad]

What's the TDS of the incoming water? What kind of unit is it?

[.OptimusPrime.]

the TDS from the IN line is around 200. It's a BRS 4 stage 75GPD that I upgraded with the 150GPD.

[F&Fmgr]

the TDS from the IN line is around 200. It's a BRS 4 stage 75GPD that I upgraded with the 150GPD.

 

do you have enough line pressure for the 150 gpd? Check the manufacturers spec sheet.

 

Sean

[Chad]

Sorry, I should have read closer!

 

If the TDS is higher than the inlet, the first thing I suspect is a faulty reading... do you have a handheld or backup TDS meter?

 

The second thing that I worry about is correct installation / plumbing. Are you sure it's right?

[.OptimusPrime.]

do you have enough line pressure for the 150 gpd? Check the manufacturers spec sheet.

 

Sean

 

I believe the specs says 65psi. I would says I do because before I would get only 3G/hr. With the upgrade its almost 6G/hr. I have timed it.

 

Unless I am wrong in that assumption.

 

Sorry, I should have read closer!

 

If the TDS is higher than the inlet, the first thing I suspect is a faulty reading... do you have a handheld or backup TDS meter?

 

The second thing that I worry about is correct installation / plumbing. Are you sure it's right?

 

No back up. I "assume" I have installed/plumbed correctly. I made ~20G of 0TDS water for a water change in about 3 hours that was almost 1.5-2 weeks ago. I haven't touched it since so I would say yes.

 

I'll try to get another reading of the in/out and post back.

 

 

[.OptimusPrime.]

Update: In has a steady reading of 199. Out started at about 150 and has managed to go down to 45 and declining slowly. Its been about 10 mins.

[.OptimusPrime.]

Units holding out at 9 TDS and not budging.

 

Is it safe to use or too high? Do LFS usually carry DI Resin?

 

Any ideas what could have happened to waste that much DI in a 3 day period? The water wasn't running or anything that I know of. Did I pack it incorrectlY?

[Chad]

If there was some sort of an issue where the incoming water hit the DI resin directly, it would eat through it very very quickly.

 

Can you post a picture of all the plumbing lines?

[.OptimusPrime.]

Front:

 

Left:

 

Right:

 

Top View Behind:

[Chad]

After spending a bit of time staring at the plumbing, it looks good. I still think the symptoms look more like the DI getting eaten up by feedwater hitting it. Is there a chance the membrane is installed incorrectly or the o-ring is improperly sealed?

[Johnny Ho]

You can also double check on the vid of instruction on BRS.

 

http://www.bulkreefsupply.com/store/150-gpd-water-saving-upgrade-kit.html

[.OptimusPrime.]

After spending a bit of time staring at the plumbing, it looks good. I still think the symptoms look more like the DI getting eaten up by feedwater hitting it. Is there a chance the membrane is installed incorrectly or the o-ring is improperly sealed?

 

Can you explain what you mean by the feed water hitting it? I re-mounted the second membrane and made sure everything is tight.

 

Do any of the LFS sell DI resin?

 

 

[.OptimusPrime.]

You can also double check on the vid of instruction on BRS.

 

http://www.bulkreefs...pgrade-kit.html

 

That's what I followed to set it up and re-checked per the video. Everything was working fine when I made the first 20G batch. Not even a noticeable dent in the resin, now two weeks later you can see its clearly exhausted but I haven't used it since I made the first batch.

[Chad]

I mean high TDS inlet water getting directly into the DI... As long as you have good resin, you will have low TDS, but it uses it up very quickly.

 

If it continues, I would contact BRS. BRK has a lot of stuff like that you wouldn't necessarily expect, I would try calling them. Other than that BRS or air water ice would be my best guess.

[Ne0eN]

What's the TDS before the DI stage?

[Big Country]

Do any of the LFS sell DI resin?

 

I bought mine at BRK, if you want to make a trip over by BWI airport I've got some to spare.

[Steve175]

Try reversing the probes on the TDS to confirm that the meter is not the problem. I have a spectrapure unit and for mine you need a higher resistance insert for the waste line with higher output membranes. Might double check that BRS doesn't have a similar requirement if that wasn't part of the upgrade kit.

[Origami]

Have you checked to see if both membranes are fully seated in their housings? If the O-ring is not making a good seal, waste-water will bypass the ring and increase TDS. Also, if there's a valve on the flow restrictor, is it set in the right position?

[.OptimusPrime.]

I mean high TDS inlet water getting directly into the DI... As long as you have good resin, you will have low TDS, but it uses it up very quickly.

 

If it continues, I would contact BRS. BRK has a lot of stuff like that you wouldn't necessarily expect, I would try calling them. Other than that BRS or air water ice would be my best guess.

 

I was thinking that I was just not used to seeing the resin get used so fast, since I was used to just 3GPH and its is now doubled but as you can see in the picture it looks like I used the resin more than the 20G I have actually made. I sent an email to BRS. Awaiting their reply.

 

 

What's the TDS before the DI stage?

 

No clue. I will probably have to check when I get home today.

 

I bought mine at BRK, if you want to make a trip over by BWI airport I've got some to spare.

 

I am usually in that area during the weekends. Off of 100. Most likely won't be this weekend, but the following week. PM your info, and I will see if I can swing by sooner. I appreciate it.

 

Try reversing the probes on the TDS to confirm that the meter is not the problem. I have a spectrapure unit and for mine you need a higher resistance insert for the waste line with higher output membranes. Might double check that BRS doesn't have a similar requirement if that wasn't part of the upgrade kit.

 

I included what you have said in the email to BRS. I will let you know what they say. I will try reversing the probes and seeing if they will show different readings.

 

Have you checked to see if both membranes are fully seated in their housings? If the O-ring is not making a good seal, waste-water will bypass the ring and increase TDS. Also, if there's a valve on the flow restrictor, is it set in the right position?

 

The original membrane should be good. I will double check the new second membrane. Wouldn't the water coming of the second membrane go to the DI canister and get filtered to 0? or are you saying the TDS thru the second membrane is too high for the resin to make it to 0 TDS?

 

No flow restrictor here.

 

 

 

[Chad]

No flow restrictor here.

 

Yes there is:

 

I don't see a flush valve on it, though. That got me thinking, though... Flow restrictors are usually specific (or a range for the GPD), is this something that was included in the BRS kit?

[Origami]

The original membrane should be good. I will double check the new second membrane. Wouldn't the water coming of the second membrane go to the DI canister and get filtered to 0? or are you saying the TDS thru the second membrane is too high for the resin to make it to 0 TDS?

 

No flow restrictor here.

The second membrane is being fed water from the waste port of the first membrane. That waste water has higher TDS than the water entering the first membrane because it's concentrated by the membrane. If the second membrane is not seated well, this waste water will flow by the membrane and come out the "pure" water port. Result: High TDS out.

 

Do you have a handheld TDS meter? If so, try this: Separate the pure water output of the two membranes (They tee together now) and take a sample of each after letting it run for a minute or so. What's the TDS out of each membrane? This will help you pinpoint where the problem is coming from.

 

Regarding the flow restrictor. You do have one, just as Chad pointed out. It may or may not have a valve on it. It's large enough, though, I almost have to think that it does. Take a look and make sure.

 

Chad, unlike the AWI 150 GPD membrane, I don't think he needs a larger flow restrictor. Instead, I think that this configuration requires more pressure at the input to drive the second membrane using pressure from the waste port of the first membrane.

[.OptimusPrime.]

Yes there is:

 

I don't see a flush valve on it, though. That got me thinking, though... Flow restrictors are usually specific (or a range for the GPD), is this something that was included in the BRS kit?

 

Doh! Guess I do have one. Sorry don't know about these things, but yes it was something that came with the kit. I have not added anything that was not supplied by BRS.

 

 

The second membrane is being fed water from the waste port of the first membrane. That waste water has higher TDS than the water entering the first membrane because it's concentrated by the membrane. If the second membrane is not seated well, this waste water will flow by the membrane and come out the "pure" water port. Result: High TDS out.

 

Do you have a handheld TDS meter? If so, try this: Separate the pure water output of the two membranes (They tee together now) and take a sample of each after letting it run for a minute or so. What's the TDS out of each membrane? This will help you pinpoint where the problem is coming from.

 

Regarding the flow restrictor. You do have one, just as Chad pointed out. It may or may not have a valve on it. It's large enough, though, I almost have to think that it does. Take a look and make sure.

 

Chad, unlike the AWI 150 GPD membrane, I don't think he needs a larger flow restrictor. Instead, I think that this configuration requires more pressure at the input to drive the second membrane using pressure from the waste port of the first membrane.

 

Go it! Thanks for explaining it to me. I do not have a handheld one. I will try and see if I can get the probes to do the readings.

 

 

 

[Origami]

Doh! Guess I do have one. Sorry don't know about these things, but yes it was something that came with the kit. I have not added anything that was not supplied by BRS.

 

Go it! Thanks for explaining it to me. I do not have a handheld one. I will try and see if I can get the probes to do the readings.

BRS doesn't show a new flow restrictor in their kit. It may have been part of your stock unit. (It's needed to maintain a positive pressure across the membrane.)

 

Wish you were closer. I have several handheld TDS meters. They're handy.

[Chad]

It's all good. Threads like this are great because I feel that a lot of folks can benefit from them!

 

I recently gave my handheld to a fellow reefer, perhaps someone close to you has one you can borrow. You can take the readings Tom is talking about with your in-line meter, but it will probably require a little extra tubing to install it in the various places.