Isolating KDF-85 into another tank????

Discussion in 'Water Softener Forum, problems, installation and r' started by royerm, Sep 24, 2012.

  1. royerm

    royerm Member

    Messages:
    92
    Location:
    Quebec, Canada
    After a lots of reading in this forum, I'm looking at isolating my KDF into another tank.

    I currently have a Greenway (Sanitizer) system which has CR-100 zeolite and KDF-85
    in a 10x54 tank with a Clack valve.

    In the beginning I only had the CR-100 to remove hardness and Iron and worked great
    for 6 months, than some H2S appeared.

    I Was instructed to add some KDF (on top/wrong) which took care of the problem
    for another 6 months, but some trace of H2S came back.
    As my media was pretty much new I decided to mix it up to extend the life of that set of media and bring the KDF to the bottom and CR100
    on top and see if the problem would be solved. According to the company the KDF should get a proper backwash this way.
    I only wish those tank were transparent to confirm ;)

    I'm now back to the original problem which is .....If I open a tap, the water has NO smell for 40 ounces than I get a smell for the next 40 ounces
    and than OK for as long as I draw water. And this scenario repeats itself very constantly.

    The company send me a new set of media to re-bed it properly, so I have that set of media on standby.

    A few question to start....

    Does the KDF need to be brined with the chlorinated water or just backwashed with water????

    I'm thinking of a second tank 10x18 (KDF) so that it doesn't get hard as a brick if not backwash properly...

    Regards....
  2. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,906
    Location:
    Ontario California
    KDF is a difficult media to do properly, and unfortunately very few companies do it properly. Personally, I think it is an amazing media that is greatly underutilized, but since so few people know how to use it, the media is highly problematic. Check out this link, it is too my system which has a KDF tank done semi-properly. http://www.terrylove.com/forums/showthread.php?45302-Prototype-system&highlight=prototype

    Kdf requires a heavy backwash. A 10" tank would require a backwash rate of 16 GPM. My own system uses a 7" diameter tank that only requires 8 GPM to properly backwash. Mixing KDF with other medias should not be done, but a lot of companies claim to have "the right way" figured out. You are on the right path. Seperate tanks for the different medias. http://www.kdfft.com/images/kdf_POESheet.pdf This is a link to the KDF application guide with proper backwash rates. In my system, I have been getting 10 years out of the KDF media with backwashing it once a month. KDF recommends a much more frequent backwashing. My design is obviously not normal, and it is designed to push the limits of what can be done and to test the different adapter types. For your application, assuming your water flow is normal (no mega showers, etc.), an 8x44 tank with 57#'s of KDF, a garnet underbed, and a good backwashing valve (7000 or 2510 is ideal), you should do ok.

    Hope this helps.
  3. royerm

    royerm Member

    Messages:
    92
    Location:
    Quebec, Canada
    Dittohead..... What got me going was actually your prototype diagram.... Sorry I made a mistake I meant 7 X18 tank for the KDF
    to have proper GPM backwash.

    So a somewhat dumm question which brand is the 7000 or 2510 valve brand name????
    Should I have a separate valve for the KDF tank and softener?????

    Should be Pressure tank/Sanitizer/KDF each having it's own cycle?????

    Still not clear if KDF is only bacwashed with water?????

    Thx
  4. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,906
    Location:
    Ontario California
    The 7000 and 2510 are from Pentair (Fleck), both of these valves are top of the line. i would recommend the SXT version for what you are doing. For the 7x18 tank... I would recommend a taller tank. The cost difference is minimal and it will look a little better than the tiny little 7x18. A 7x44 is common stock for most companies.

    The KDF backwashes with water, NACL will not affect it. So in my system design, the KDF is neither harmed nor helped by the salt.

    You could attempt to use a single valve/softenr valve design, but... considering what you are trying to accomplish, and because it is after the fact, a seperate system would be easier. The main advantage to a shared valve system design is the backwash savings, but it is also a hinderance, The KDF should be backwashed more frequently than the water softener. In my old system, the KDF looked like new after 10 years of service being backwashed monthly. Your milage may vary. Every 3rd day backwash is the norm for KDF.
  5. royerm

    royerm Member

    Messages:
    92
    Location:
    Quebec, Canada
    Ok so in series.....Softener than KDF????
    Actually the company recommend every 4-5 days for the CR-100 stuff.
    Can the fleck valve adjust the water flow for backwash??? as I presume that a 7" would require 7-8 GPM...

    Thx
  6. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,906
    Location:
    Ontario California
    I prefer to put the KDF first since it is a very strong media (ground up zinc and copper) that should last a very long time if you backwash it adequately.

    A 7" tank requires 25 GPM per sq. ft., so...

    3.5 x 3.5 x 3.14 / 144 x 25 = 6.7 GPM so yes, a 7 GPM button would be proper. If your water is clean, then every few day would be fine.
  7. royerm

    royerm Member

    Messages:
    92
    Location:
    Quebec, Canada
    So to recap, it would be Pressure tank - KDF - Softener - House ??
    How much KDF do you suggest ???
    How many minutes for the Backwash of the KDF?????

    I have 16 pounds that was sent for re-bed by the company, if more than 16 pounds
    is required, any trick to salvage what I already have in the softener????

    Your help is much appreciated.....
  8. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,906
    Location:
    Ontario California
    Correct,

    KDF, I suggest 40+ pounds in a 7" tank, be sure to use a high quality fine mesh screen like the the Fleck 40922 bottom screen and a heavy underbedding of garnet, at leat 2-3 inches above the screen.
    Backwash for 10 minutes at 7-8 GPM. I usually do 7 gpm if the water temperature is below 70 degrees, this is easier anbd cheaper than 8 GPM< thiswould usually require a different drain adapter design with the Fleck valves.

    Backwash every 3-5 days depending on the water quality and water usage. My own system design uses 30 pounds with regeneration done every 30 days. My KDF sees no sediment, and is fed with softened water. Even my old design was fed with hard water and regenerated every thirty days, it is still being used after 13 years. I did replace the KDF after ten years, and it looked excellent at that time and was still removing 95+% of the chlorine in my municipal supply.

    Salvaging what you have in the softener? Difficult and very time consuming. It could be done by screening the differant media sizes through screens, but not sure if it would be worth the effort. If you leave it in your old tank, it will probably just turn into a clump at the bottom of the tank and have ne negative affect in the future. http://www.kdfft.com/images/kdf_POESheet.pdf
  9. royerm

    royerm Member

    Messages:
    92
    Location:
    Quebec, Canada
    OK thx...
    Just to clarify , in my case the KDF is to remove the H2S from well water,,,,,,Everything still applies?????
Similar Threads: Isolating KDF-85
Forum Title Date
Water Softener Forum, problems, installation and r Debrief of my Cr100 with KDF-85 problem Apr 6, 2012
Water Softener Forum, problems, installation and r CR100 with KDF-85 Mar 7, 2012

Share This Page