Help me understand when is best to change which filters on my RODI unit please.

Discussion in 'Bulk Reef Supply' started by fishbox, Oct 13, 2017.

  1. fishbox

    fishbox Well-Known Member

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    [​IMG]

    What the freak is going on here?!?!
    I installed the new membrane from BRS today in which I am very thankful for! However, it still didn't solve the issue. TDS after the membrane is actually higher now at 32.

    After installing, I disconnected the line coming out of the membrane that goes into the DI and I ran the unit for 1 hr bypassing the DI with the flush valve off as suggested. You can see exactly where I bypassed in the video below. During this hour I continuously checked the TDS coming out of the RO membrane with my hand held and it never dropped below 38 TDS.

    After that I hooked the DI backup and and flushed for another 5 minutes and now I'm getting 32 after the membrane going in to the DI with both the handheld and the inline TDS meters.

    I verified once again that my tap water is 172. I can't figure it out but I'm only getting like a 80% rejection rate which is not right. Could it be that the housing for the membrane is bad?

    Below is a link to a video I'm hoping you guys can check it out just to verify my line placements and you can also see where I bypassed the DI

     

  2. cmcoker

    cmcoker Well-Known Member R2R Supporter R2R Excellence Award Build Thread Contributor

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    I would verify your restrictor is working properly. Take a couple measuring cups, run product water into one, waste water into the other, run system for 1 minute and see what the ratio of product to waste water is. Maybe the restrictor is faulty.
     
  3. fishbox

    fishbox Well-Known Member

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    Thanks cmocker. I'll try that. Does my line placement look ok?
     
  4. Zack@BRS

    Zack@BRS Active Member R2R Supporter Gold Sponsor

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    That's a serious bummer! From what I can see, your lines and probes all appear to be properly connected. At this point, there are a limited number of possibilities we could run through. It *could* be a damaged membrane housing allowing leak-through of reject water, but I've never personally seen this. There may be an issue with the flow restrictor not forcing the proper ratio of product to waste, and this should be easy to verify and resolve if it were the case. Another unlikely scenario could be that the auto shut off (the device with 4 ports in back) has a leak in the diaphragm, allowing feed water to mix with product water. If this were the case, you would likely see an issue with the asov working and water would continue to run down your drain when the product line has shut off. It might be helpful to get a water quality report to see what's in your water. While a membrane will reject the majority of contaminants, there are a few organic and inorganic contaminants that the membrane can have a hard time with, and if they are in higher than normal concentrations, this might result in odd rejection rates.

    We'd be happy to work through each of these possibilities with you, but if it's less of a hassle, we could also get that unit back here to identify and resolve any issues. Please feel free to pm me and let me know what next steps you'd like to take, or you can also reach out to any of our customer service team by phone, email, or live chat.
     
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  5. Cronicreefer

    Cronicreefer Well-Known Member

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    All of your lines are installed correctly. It sounds like you may have a bad RO membrane (assuming your rejection rate is correct at 3:1 or 4:1). I use membranes/resin from a company called Spectrapure that work really well for me. My RO membrane is going on 3 years old and is still producing <3 TDS after membrane. If your rejection rate comes back at 3:1 or 4:1 I would just consider getting a new RO membrane. A 98% rejection rate membrane will also help your DI resin last much longer than 95% rejection membrane, it sounds like a small difference but it can go a long way over time. If your water contains chloramines and you do not have the right carbon block it could be damaging your membrane also resulting in the poor TDS rejection. You'd need to look at your local water providers water quality report to find this out. If it does contain chloramines I believe you will need a carbon block rated at 0.5 microns to remove them properly.
     
  6. fishbox

    fishbox Well-Known Member

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    Zach you guys are truly awesome and I really really appreciate all your help man. If you don't mind I prefer to continue to deal with you since you already know my situation and where I've been. Plus I like your style brother LOL. I will send you a p.m. a little bit later this evening after I'm done studying. Again thanks for all your help.
     
  7. fishbox

    fishbox Well-Known Member

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    I highly doubt at this point it's the membrane. If you read the post a little deeper you'll see that we thought it was the membrane and that BRS sent me out a new one which I just replaced but I'm still having the issue
     
  8. Zack@BRS

    Zack@BRS Active Member R2R Supporter Gold Sponsor

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    I'm happy to be able to help! We'll get you squared away shortly.
     
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  9. Forsaken77

    Forsaken77 Well-Known Member

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    This may seem like a stupid question, but are you positive you don't have the waste water line from the membrane going to the DI resin and the product water (good water) going down the drain? Sometimes people mix them up accidentally.
     
  10. fishbox

    fishbox Well-Known Member

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    Man nothing is wrong with that question at all as this ran through my head earlier while testing. That's why I posted the video above asking about my line placement. Which it has been confirmed I have them correct. Again, my product water is 0, after the RO membrane it's now 30, and my tap water is 172. For and giggles, I also tested my wastewater at 245.
     
  11. Cronicreefer

    Cronicreefer Well-Known Member

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    I'm just going to rule out that the seals are bad on your unit since it seems you already checked this multiple times. I did a little research on your membrane and I believe your issue is related to the chloramines in your water. Your membrane is rated at being able to handle less than 0.1ppm of free chlorine. This low rating basically means that if any chlorine is present it is going to degrade your membrane within 200-1000 hours of runtime. Chloramines are even worse when it comes to oxidizing the RO membrane. Only a carbon block rated at 0.5microns will remove chloramines from my understanding and I believe if you purchased one you would see much better life and quality of permeate out of the membrane.
     
  12. fishbox

    fishbox Well-Known Member

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    I understand what you're saying but that would not explain how I literally put in a brand new membrane today and and still only seeing an 80% rejection rate. Which is what I've been seeing since I installed the unit 7mos ago. The membrane has not really gotten any worse since day one. The problem is that its always been that bad since day one and after replacing the membrane my numbers didn't change.
     
  13. cmcoker

    cmcoker Well-Known Member R2R Supporter R2R Excellence Award Build Thread Contributor

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    As far as I can tell yes. Hope it all gets sorted out!
     
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  14. Forsaken77

    Forsaken77 Well-Known Member

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    Did you verify you have the carbon block for chloramines? Maybe they sent you a regular carbon block? And line placement can be tricky. Just to make sure, your waste line has a LOT more coming out than the product line, right? That's the sure fire way to tell which is waste and which is product.
     
  15. fishbox

    fishbox Well-Known Member

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  16. fishbox

    fishbox Well-Known Member

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    So the saga continues.....

    I did a wastewater to product water ratio test for 2 minutes. I got 1325 ml of wastewater and 650 ml of product water. The calculator in my head is a little old and rusty but I think that's pretty much a 2:1 ratio. I'm not sure what that tells us. Someone please enlighten me.

    I also used my LaMotte test strips for free and total chlorine. The first picture is from after the carbon block but before the membrane and the second picture is from the waste water. The both look like 0ppm to me.

    [​IMG]

    [​IMG]


    I'm having trouble understanding this. Are you saying to test the asov by blocking off the product water line?
     
  17. cmcoker

    cmcoker Well-Known Member R2R Supporter R2R Excellence Award Build Thread Contributor

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    Yes you block the product line to check the asov. It will take a little bit to build enough pressure. And it sounds like you need to try a new flow restrictor to get more along a 1:4 ratio
    Chlorine looks negative to me too
     
  18. fishbox

    fishbox Well-Known Member

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    Zack mentioned seeing water go down the drain if I blocked the product line but exactly where would I see that water come from?
     
  19. cmcoker

    cmcoker Well-Known Member R2R Supporter R2R Excellence Award Build Thread Contributor

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    The waste water line will still run until the asov closes. If the waste line doesn't stop, after the unit has built enough pressure, the asov is faulty
     
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  20. fishbox

    fishbox Well-Known Member

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    lol... It does exactly what it says! Why didn't I pick up on that

    But thanks cmocker. I'll check it out tomorrow.
     
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