Discussion in 'Equipment' started by Rostato, Nov 14, 2018.

  1. Rostato

    Rostato Supporting Member

    I live in Fremont, and they use Chloramines to treat local water.

    Ive been using 2 of BRS’s universal carbon blocks with the ro save Z depth sediment filter in front of them. I’m using this on a kinda diy/ Frankenstein 5 stage Rodi setup with a 75gpd membrane

    I’ve probably only made about 500 gallons (product water) and already am seeing a pressure drop off and high di resin usage.

    My question to all of you is what do you do to help maximize water production while filtering the Chloramines? I feel like replacing all of those cartridges for every 500 gallons of product water is very cost prohibitive. There’s gotta be a better way.

    Should I just get a whole new system?
  2. OnTheReef

    OnTheReef Supporting Member

    Just from your description, it’s hard to offer any specific advice on your homegrown system. However, I’ve now owned two different RO/DI systems and have had excellent results with both of them:
    Air, Water, Ice Typhoon III
    Spectrapure MC-RODI-180-10MF
    With both units, I found the cartridge kits to be the best value for my money and replacing all cartridges at once to be the best strategy for media life.
    I think both of these companies are sponsors, so you may find an incentive to purchase one of their units.

    Sent from my iPhone using Tapatalk
  3. Coral reefer

    Coral reefer Past President

    How many gallons are the carbon blocks rated for? What ratio of product to waste are you getting? Was the membrane new when you set it up? How's long has it been in use. What micron is your sediment filter? What pressure are you getting when cartridges are new?
  4. Coral reefer

    Coral reefer Past President

    I use an extra 20" 5 micro sediment filter before my regular 1 micron sediment filter. This traps most of the rust etc before it can clog the 1 micron. This is important so that it catches most of the small stuff so it doesn't clog up the carbon block before it's useful life is spent.
    Very highly recommend using multiple membranes in line. Waste from one into supply of the next. You need good pressure or a booster pump for this. It's worth it. You will make water faster, and basically double the product water you are getting during the useful life of your prefilters.
    If your membrane wasn't new, and or hasn't always had good chloramine removal it could be wrecked. This would lead to extra di resin use. Also starting and stopping the filter a lot will cause this.
  5. Rostato

    Rostato Supporting Member

    All very good questions.

    I’m getting 3 tds out of the membrane right now, but I realize that doesn’t tell me exactly how much ammonia the di resin is having to remove. I also flush the membrane for 15 minutes every time I run it. I run it once every 2 weeks and run it all day. I basically fill up my 32 gallon brute full and also my 10 and 5 gallon top off containers. Usually run at least 20 gallons of product water minimum every time I turn it on.

    When filters are new I’m getting about 60 psi. As of the other day I’m at like 45 psi.

    I honestly have no clue what membrane is in the canister, but it’s definitely not very efficient.

    I’m using the 1 micron sediment’s this one

    And 2 of these 1 micron carbon blocks
  6. Rostato

    Rostato Supporting Member

    I didn’t know Spectrapure was a sponsor...that does help if they are.
  7. Rostato

    Rostato Supporting Member

    The carbon blocks say 2000 g of cloramines at 1 gpm...but that’s pretty slow contact time. To me that basically means nothing because I can’t slow down the water contact time on the carbon blocks and then speed it back up for the membrane.

    At least I think that’s not possible.
  8. rygh

    rygh BOD

    I am really surprised by the pressure drop through your prefilters. (60 -> 45)
    That implies you may have a lot of sediment/rust in your lines.

    My suggestions:

    1) Replace your 1 micron filter a LOT. Like every couple months. As soon as pressure drops a bit.
    Get a box of them, they are pretty cheap.

    2) Get refillable activated carbon canisters.
    With refillable, it is also pretty cheap, so you can replace them a bit more often.
    That should solidly fix your chloramine problem.

    3) Remember to flush water bypassing membrane when changing carbon.
    The carbon fines from replacing them will kill your membrane.
  9. Rostato

    Rostato Supporting Member

    Good info. I’ll replace the sediment filters more.

    But my understanding is that most carbon doesn’t remove chloramines. And I believe refillable Carbon cartridges won’t have nearly as much carbon packed inside them as the throw I wrong here?
  10. sfsuphysics

    sfsuphysics Supporting Member

    do yourself a favor, get some of those chlorine test strips from BRS, you can test the water right after all your prefilters just to verify if chlorine or chloramine is making their way through
    Rostato likes this.
  11. Coral reefer

    Coral reefer Past President

    Pretty sure they are not. Air water ice is. Their banner pops up at the top of the website.
  12. Coral reefer

    Coral reefer Past President

    Do the math. You are not flowing more than 1 gal per minute. That would be 15 gal product water per hour. Contact time is not likely your issue. Especially since you have 2 blocks in a row.
    I am fairly certain your blocks are getting clogged. Try changing or even removing the first block and see what effect it has on pressure.
    Also, if the block Is rated for 2000 gal you have basically hit that once you end made 500 gal product water. At least the first one Is spent, And likely clogged.
  13. Coral reefer

    Coral reefer Past President

    This is what you want. Trust me. Been there. Done that.
    OnTheReef likes this.
  14. Coral reefer

    Coral reefer Past President

    80 psi would get you better performance out of the membrane. Get a booster pump. Trust me. Not sure why you say the membrane you have isn't very efficient? None of them will work as expected at lower pressure. The gpd they are rated at are basically at 80-90 psi and a higher temp than we typically run them at. Also, it's important to have the proper flow restrictor. What's yours like?
  15. rygh

    rygh BOD

    Carbon does remove chloramine, but slowly.
    So you need good activated carbon with lots of surface area, and long contact time.
    Since water drips through, contact time is usually pretty good in our RODI systems.

    Those carbon cartridges have a big empty hole in the center, while refillable do not,
    so I would guess volume is similar or better.

    But the refillable ones do not filter sediment like the cartridges.
    Big holes between carbon chunks you put in there, not a 1 micron filter.

    I use one of each in my setup.
    Rostato likes this.
  16. Rostato

    Rostato Supporting Member

    for Flow restrictor I’m using the BRS combination restrictor / flush valve.

    Thanks for all the info from everyone. I have a lot to ponder on. I kinda just wish there was a turn key solution that didn’t take up much room in my wife’s laundry room. But I guess you gotta pay to play.

    A booster always seemed like an overpriced novelty to me but maybe I need to rethink that.

    Anyone ever heard of the cloramine monster?
  17. Rostato

    Rostato Supporting Member

    I was thinking one gallon a minute was pretty easy but after putting some real thought into it I guess your right. That really sucks. I just need to pony up the money for more filters regularly is what it seems like to me.
  18. James Oh

    James Oh Guest

    I was meaning to see if chloramines were making their way through my RODI unit as well so I looked this product up on BRS and it seems a lot of people are saying that the test results failed them. (their tap was reading 0 when it shouldn't) Have you had problems with this too?
    Rostato likes this.
  19. Coral reefer

    Coral reefer Past President

    An extra sediment canister, booster pump, and second membrane will not take much room, and will eventually pay for themselves.
    $100 for a booster pump is not wasted money. If that's too expensive, I hate to say, you may Be in the wrong hobby...
    If it's worth doing it's worth doing right.
  20. Coral reefer

    Coral reefer Past President

    Also, when I asked about the flow restrictor I mainly antes to know how many ml per minute it lets through?

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