Kalkwasser potency

Discussion in 'Reef Chemistry' started by HiFidelity, Sep 30, 2013.

  1. HiFidelity

    HiFidelity Guest

    Hi gang,

    I just barely stopped using 2-part & switched to kalkwasser, I made my own by mixing 1 tspn of Mrs. Wage's in a gallon of RO/DI water and started dosing it, I've gone up to a quart a day of the solution but PH & ALK are not budging, if anything it's just maintaining ALK at 8 or so, I know if I don't dose anything my ALK will drop lower than that.

    I want to bring my PH up above 8.2 from 8, and ALK up to 9-10 from 8 so my question is how strong should my solution be? is 1 tspn/gal too light of a mix? I'd love to hear what your recipes are.

  2. Hey Fidel, you probably already know that saturated kalkwasser is typically considered to be 2 teaspoons of calcium hydroxide per gallon of water. Is there any particular reason you are using unsaturated kalkwasser?

    Take a look at this online calculator. For instance, you can see that for a net water volume of 25 gallons, adding 0.2 gallons saturated kalkwasser will increase alkalinity from 8 dKH to 9 dKH, assuming no consumption of alkalinity by organisms, reaction with CO2, etc. This could give you a good idea of the alkalinity consumption going on in your tank and how much kalk you need to be dosing in order to maintain your levels.

    Depending on the rate of evaporation it may not be feasible to increase alkalinity using kalkwasser, in which case you could use sodium carbonate or sodium bicarbonate from your 2-part supplies to gradually increase alkalinity until you are at 9 to 10 dKH, then use kalkwasser to maintain it at that level.

  3. HiFidelity

    HiFidelity Guest

    I guess I went with just one tspn because many people on the web suggest you start there if you're a newbie to kalkwasser then increase the amount after...
    Also I figured it would drive alkalinity up because of all the threads I've read where dosing kalkwasser did result in increased ph as well as dKH! I'm really trying to get away from the 2-part stuff because I don't ever need to dose calcium and the 2-part is always designed to be dosed together...
    I'll adjust the amount & go from there, my first gallon is practically gone anyway, next batch will be 2 tspn lime.
  4. sfsuphysics

    sfsuphysics Supporting Member

    Kalkwasser is neat too in that you can't "waste" it, if you put in a cup of lime in a gallon of water mix that up it'll reach full saturation with the rest settling, but then when you add more water it'll simply saturate that as well.
    Basics for how a kalk "reactor" works, dump in a ton of lime, then just hook it to a freshwater source to top off as necessary.
  5. Sounds good, Fidel! Considering that 1 tsp/gal kalkwasser is just maintaining the level of alkalinity, your two choices are to add more than 1 qt of kalk per day or increase the kalk saturation. Personally I find it easier to always use saturated kalkwasser, and change the amount dosed as needed.

    Are you dosing the kalk by drip or a slow feed pump in a high flow zone?
  6. HiFidelity

    HiFidelity Guest

    Mike thanks for pointing that out, I was about to throw away the stuff that settled on the bottom.

    David thanks for the valuable insight, I'm going to increase the saturation and right now it's dripping 24/7 from a 1 qt bottle into the output stream of my skimmer into the sump.
  7. Randy Holmes Farley has a knack for explaining reef chemistry - always good reads!
  8. newhobby

    newhobby Guest

    Do you mix the super saturated water through the week or only when you add more water to it?
  9. sfsuphysics

    sfsuphysics Supporting Member

    It shouldn't matter too much, personally if you have a "reactor" then it'll do the mixing for you, and nicer designs use the water you add to it as a way to push the kalkwasser into your tank. However if you have a 2 litter bottle or something that you do a once a day dosing, after you pour some out for your tank just swish it around a bit. Unless you have a very large container of saturated kalkwasser you really shouldn't lose potency much
  10. HiFidelity

    HiFidelity Guest

    I only stir it when I first mix to minimize degradation, I think I got a handle on getting the kalkwasser fully saturated but now I'm not sure how much I should be dosing; I'm doing about 1 qt a day when lights are off and I'm seeing little affect on the PH and dKH, PH is being swayed upwards more than dKH is changing... does 1 qt/day in a 45 gal tank sound right?

    I'm trying to get the amount right since I got my hands on a couple of dosing pumps, 2 peristaltic pumps one is BRS 1.1ml & the other is adjustable which I plan to run into a 5 Gal bucket of top off water (based on which suits the desired amount)...
  11. sfsuphysics

    sfsuphysics Supporting Member

    IMO, use calculators only as a rough estimate to how much you should dose. Test your water before you dose, dose, then test it again the next day, that'll give you an indication to if you are dosing way too much, or way too little.

    The problem with these damn corals is they grow, and as they grow they consume elements at a faster rate so the 1 cup a day dosing that you did when your tank was full of tiny frags won't be nearly enough when all those frags are minicolonies.
  12. HiFidelity

    HiFidelity Guest

    I think I'll fire up my adjustable peristaltic pump in the next couple of days & top off 1/4 gallon of saturated kalkwasser when the lights are off over several hours that way I can establish consistency (can't quite accomplish that with dripping) and do daily measurements to see what happens. 1/4 gallon is roughly my daily evaporation rate.
  13. HiFidelity

    HiFidelity Guest

    Got my ATO going, it's a LKB Varioperplex II adjustable rate peristaltic pump running on a digital timer, it runs 6 times a day while the lights are out at 20 minute intervals once every 2 hours, water is pumped from a 5 Gal arrowhead water cooler bottle (narrow neck) and into the skimmer output. The top off water consists of 5 tspns of lime in 5 gallons of water, I'm going to play with the pump till I get the right ratio to balance out evaporation while testing alk/ph every day or 2 to see if there are any changes then if needed I will adjust the potency to a max of 10 tspns in the 5 Gal container.

    So far by dripping my PH has hovered around 8-8.2 and 8 dKH so I have head room in case it climbs from there.

    What do you guys think?
  14. rygh

    rygh Supporting Member

    Note that evaporation varies. Depends on air temperature and humidity, and will be seasonal.

    I am not a fan of connecting ATO to Kalk anyway.
    To many things can go wrong, and all you save is one pump.
    Have a nice dosing pump for the Kalk, so you can carefully regulate it.
    Then have a separate ATO.

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