So what are people using for a RO/DI system?

Discussion in 'Equipment' started by sfsuphysics, Oct 21, 2017.

  1. xcaret

    xcaret Supporting Member

    Canisters are clear...
     
  2. sfsuphysics

    sfsuphysics Supporting Member

    That could be useful.
     
  3. Vincerama2

    Vincerama2 Evil Overlord

    Mine started life as an AquaSafe RO/DI unit, then over the years I've replaced a lot of part so that not even the original bracket is in use. So mine is just an RO/DI unit that gets parts replaced as needed. Not even really a "unit" anymore so much as a bunch of parts.
     
    ashburn2k likes this.
  4. sfsuphysics

    sfsuphysics Supporting Member

    Really need to use the TDS tester more often, about 80 coming out of the RO membrane which is a definite sign of membranes being toast (or a bad TDS meter :D). Explains why my DI resin went bad so quickly though. Oh well, new membranes on the way (amazon prime) and some parts from BRS to throw together a 3 stage DI resin area (Cation, Anion, Mixed Bed). Well see how well that works out. I was leaning toward 20" filters for the resin, but now I'm thinking that may be a bit overkill.
     
  5. rygh

    rygh Supporting Member

    I have a simple 4 canister + extra pre carbon filter. Color changing DI is refillable, saves money.
    Extra carbon for Chloramines, seems to increase life of DI resin.
    I really think people worry way too much about water quality in.
    You look at all the food you put in, and it WAY dwarfs and nitrates/phosphates from RODI.
    For me, I just want to make sure no copper or Chloramine gets in.
     
  6. sfsuphysics

    sfsuphysics Supporting Member

    That would be something interesting worth looking into the numbers. What's 2 teaspoons of food in 200 gallons of water translate to?
     
  7. RandyC

    RandyC Guest

  8. sfsuphysics

    sfsuphysics Supporting Member

    Seems to be counter intuitive to what Mark is saying though, it says adding 1 reef prime cube is the equivalent of adding 0.022ppm of phosphate daily, so double that and we have 0.044ppm. If you had a TDS reading of 4.4 ppm that's 100 times more. Granted TDS is not simply phophate (if it is at all phosphate), but seems to be having dirty water actually adds a crap load (yes pun intended) of stuff to your aquarium above and beyond phosphate.

    Now that real question is what exactly are the dissolved solids that make up TDS.
     
  9. rygh

    rygh Supporting Member

    Don't bother with TDS for that. Just check phosphates with a test kit directly.

    But sorry, I did not mean to imply you should use tap water directly. That could introduce a lot of phosphates.
    After RODI it should be very low.
    But of course, if RODI is not working....

    My favorite article on phosphates
    http://reefkeeping.com/issues/2006-09/rhf/index.php

    And a key quote:
    "... if five grams of flake food is added to a 100-gallon aquarium, there is the potential for the inorganic orthophosphate level to be raised by 0.4 ppm in that SINGLE FEEDING!"
     
  10. sfsuphysics

    sfsuphysics Supporting Member

    Well yeah after RO/DI .. I'm going to assume it's working unless TDS says otherwise. I just want to set things up for ultimate "ease of use", whether that means maintenance on filters (hence the discussion of the 20" filters) or ease of packing resin into those little containers (which always seems to be a pain in the ass for me which is why 10" might be best even if I have to change it twice as often as a 20" cannister).

    5 grams of flake food is a lot though, 1/14th of those smaller Ocean Nutrition cans.
     
  11. xcaret

    xcaret Supporting Member

    Haven't forgotten about the clear canisters, just been busy a little more than usual. As a side thing, I picked pair of the long canisters on a bracket, they have carbon blocks but they are white.
     
  12. sfsuphysics

    sfsuphysics Supporting Member

    No worries Mario, the solid ones I have will do for now. I'm just thinking about the DI resin canisters. Unfortunately BRS is all out of the Anion resin, seems like a lot of other people are doing the separate bed method.
     

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