How do kalk-reactors work?

Discussion in 'DIY' started by sfsuphysics, Sep 27, 2007.

  1. sfsuphysics

    sfsuphysics Supporting Member

    Decided to put this here because I plan on modifying an old skimmer to be a kalk-reactor
    Ok I know basically you toss in a bunch of kalkwasser and it has a pump that stirs it... but beyond that what?

    First I'm guessing the pump is only on periodically to mix the stuff back up?
    Second how does the lime-water get into the tank? Is it something you put on a float switch/auto-top off? Is it plumbed in directly to your RO/DI source? You don't pull tankwater and mix do you? Or do you set it for a slow drip/peristaltic pump?

    Finally I'm guessing you want to make it air-tight so as to minimize the precipitation of lime-water along the surface.
  2. Mr. Ugly

    Mr. Ugly Past President
  3. Mr. Ugly

    Mr. Ugly Past President

    Looks like Randy is happy with just a big container of kalkwasser and a diaphragm pump. And he doesn't bother with remixing the kalk.
  4. Paradox

    Paradox Guest

    I chose to just add kalk into my top off resevoir also. A lot cheaper and easier in my opinion. The only difference with a using a kalk ractor is that you can go longer before adding more kalk to the reactor. The reactor can contain much more kalk than that water can absorb. When rodi enters the reactor, the stirring/mixing device will saturate it with kalk prior to entering the system. If your using a container like a top off resevoir, you mix it once and slow dose it to the tank. My 20 gallon container lasts 3 weeks, and refilling just means turning on a vavle to fill it with rodi, then dumping kalk in, mix and your done.
  5. northbay-reefer

    northbay-reefer Honorary Member

    Kalk reactor works like this.

    fresh water enter the chamber from the bottom, mixed with kalk using the pump half way up the chamber that is mounted upside down so the kalk and water mixture doesn't penetrate the upperpart of the reactor. Once the pump stops, the kalk will settle to the bottom. The clear liquid is drawn from the top of the chamber and enter the tank or sump. I usualy mix the kalk this way twice a day for 10 minutes
  6. GreshamH

    GreshamH Guest

    I've noticed a difference since I've stepped up my mixing to every 15 minutes on for 33 seconds. It didn't do much when it was at half that, so I jumped it up :)
  7. northbay-reefer

    northbay-reefer Honorary Member

    Gresham, its depending on how you are using it, I use it as my top off to counter the drop in PH when I use the calcium reactor so I don't need to use that much kalk. But if you are using it as your primary souce of calcium then I would step it up too.
  8. how u guy program the Ac Jr to turn on the pump 33 second every hours on the reactor.Thanks

  9. Raddogz

    Raddogz Guest

    Mine is not set to 33 seconds but set to turn on for five minutes every four hours.

    OSC 005/240 ON/
    Then KLK ON

    KLK is what I named reactor.
  10. GreshamH

    GreshamH Guest

    [quote author=northbay-reefer link=topic=2451.msg25209#msg25209 date=1191008523]
    Gresham, its depending on how you are using it, I use it as my top off to counter the drop in PH when I use the calcium reactor so I don't need to use that much kalk. But if you are using it as your primary souce of calcium then I would step it up too.

    It's not my primary. To keep my PH high, I need it to run a lot :) I was having a hard time for a while keeping my PH up, no matter what I threw at at :( I't's golden now though, it's all clicking again!

    Lap, I use a Green Air CyclStat2 to do that. It's just a repeat cycle timer. I just set how long for it to be on and how often to be on :)
  11. capescuba

    capescuba Supporting Member

    There is really no such think as a Kalk Reactor - There is no "reaction" as far as I know, just some mixing going on. Doesn't sound as ambitious though does it, Kalk Mixer!
  12. northbay-reefer

    northbay-reefer Honorary Member

    capescuba, Your statement is not totaly true :D kalk is mixed with RO water which has low PH, the low PH is what help melt the kalk easier. So their is some reacting going on in there :D :D
  13. GreshamH

    GreshamH Guest

    You don't call the bufferring of low PH to a high PH a reaction? While I'm no chemist, I do know there's a reaction when you toss low PH into high PH, it gets higher. It also boosts the alkalinity levels as well as the calcium levels.
  14. capescuba

    capescuba Supporting Member

    Ok - I take my naive, ill informed words back! After what, 11 years :D
  15. BAYMAC

    BAYMAC Guest

    lol NBR and I might have been a little harsh :)
    capescuba likes this.
  16. rygh

    rygh Supporting Member

    For fun:

    This is the chemical reaction in the reactor/stirrer when you mix in the kalk.
    CaO + H2O -> Ca(OH)2
    produces heat also.

    This is the reaction in your tank
    Ca++ + 2(OH-) + 2(CO2) <==> Ca++ + 2(HCO3-)
    As it produces calcium and bicarbonate.

    What you don't want is this:
    Ca++ + 2(HCO3-) + Ca++ + 2(OH-) <==> 2 CaCO3 + 2 H2O
    If CO2 is too low / too much Ca+Alk, you get precipitation.

    PS: I totally copied those formulas from the web. I am not that much of a chemistry expert.
  17. sfsuphysics

    sfsuphysics Supporting Member

    Well since I'm just a dumb physics teacher, and this is my 10 year old thread... one question that pops out at me is the output of the reactor is Ca(OH)2, I'm assuming in chemistry speak that is a single molecule. The in tank reaction starts as Ca++ + 2(OH-) + 2(CO2) =.. but how does it really split up in the tank where the calcium snatches the electrons on the hydrogen? Does it really split up or does the carbon dioxide create some reaction with the original molecule and that's just the way dumb chemists write down math where they skip steps? Because I would think you would write it down as Ca(OH)2 + 2(CO2) <==> Ca++ + 2(HCO3-).

    I know this is just a copy and paste, but to me it says some other reaction happened to split up the kalk reactor slurry that came out, where as the way I wrote it simply shows that the kalk output gets broken up when more favorable opportunities come up with the CO2 in the tank (too-timing cheatin' charges!!!)
  18. rygh

    rygh Supporting Member

    Yes, the formula is skipping steps.
    Look up ionic reaction in an aqueous solution.
    (But no, I don't know the exact full equation)
  19. rygh

    rygh Supporting Member

    Funny on the necro-thread

Share This Page