surf&turf January 16, 2012 January 16, 2012 I already dose Kalk. Adding vinegar seems like a no brainer, what do you guy's think Sorry for the long post. HOME | GALLERIES | E-ZINE | RESOURCES KALKWASSER | IN DEPTH (reprinted with Breefcase's permission from works written in reefs.org) When Calcium Hydroxide solution (Kalkwasser) is slowly dripped into your aquarium, it captures free Carbon Dioxide present in the tank water and converts it to Bicarbonate ions (which is a good thing), like this: Ca++ + 2(OH-) + 2(CO2) <==> Ca++ + 2(HCO3-) If you drip too fast or if there is not enough Carbon Dioxide available in the water, your shiny new Bicarbonate ions will be converted to Carbonate ions (a bad thing), like this: Ca++ + 2(OH-) + 2(HCO3-) <==> Ca++ + 2(CO3--) + 2 H2O The Carbonate ions formed will make the Ca++ you are trying to add to your tank get wasted by the useless precipitation of Calcium Carbonate -- the white stuff you are seeing. So, too rapid addition of Kalk may actually cause the Calcium and Alkalinity in your tank to go DOWN instead of UP (a bad thing), like this: Ca++ + 2(HCO3-) + Ca++ + 2(OH-) <==> 2 CaCO3 + 2 H2O In the above reaction, a Calcium ion and two Bicarbonate ions from the aquarium combine to form solid calcium carbonate -- the white stuff you are getting in your tank, which is really just a kind of sand. This can happen even with a slow drip of Kalk if there is not enough CO2 in your water -- something you can't easily control. To avoid this, try mixing and adding your Kalkwasser like this: pour 15ml of 5% Acetic Acid (or ordinary Distilled White Vinegar from the grocery store -- same thing) into a 1 liter (1 quart) container. Dissolve 1/2 teaspoon of lab-grade Ca(OH)2 (or commercial Kalkwasser mix) in the Acetic Acid, and then dilute to 1 liter (1 quart) volume with either RO/DI water, or even tank water. 15 ml is more Vinegar than some people are comfortable with, but I use it constantly with no problems. There should be no sediment in the mixture, or just a little bit at most. You can let the sediment settle out if you don't like the white flakes in your tank. I just drip the liquid and the sediment both into my tank. Dissolving the Kalk powder in the Vinegar first will accomplish several very good things. First, it will get more Calcium ions (Ca++) into the solution because you are dissolving the Ca(OH)2 in an acid instead of water, and forming Calcium Acetate, which exists as a dissociated equilibrium of free Calcium ions and Acetate ions. Second, the Acetic Acid (Vinegar) provides an equivalent of all the CO2 you need to avoid precipitating the newly-added Calcium ions as useless white Calcium Carbonate powder. Third, after all the cool Calcium ion chemistry is over, the leftover Acetate ions from the broken-down Vinegar leaves you with free organic Carbon in the water that feeds the bacteria in your tank so that it converts more poisonous Nitrates to NO2 gas (a very good thing). Adding Vinegar in Kalkwasser is one of the few win-win situations for reefers -- it has a great up side and I've yet to encounter a down side to doing it. I don't know why so few reefers do it -- lack of understanding of the chemistry behind it maybe -- but a lot more are starting now that some respected reef writers have discovered it and have recommended it and even written up detailed instructions for it. By the way, you should check your pH before and after you do this the first few times to make sure it is not affected by the process. It should not be a problem. Also, if you don't already have them, get and learn to use Salifert test kits for Calcium, Alkalinity, and Magnesium. The levels of all of these are related and affected by dripping Kalk. The advice not to mix the Kalk too much is right on target. As the equations I posted show, if you are not using any Vinegar in the mix you certainly DO need to avoid mixing the Kalk powder with CO2 until AFTER it's dripped into the tank. Look again at the equations. Both the GOOD reaction that liberates useful Calcium ions (Ca++) into your tank, and the BAD reaction that wastes the Calcium ions as solid Calcium Carbonate (CaCO3), require the addition of different amounts of CO2. The problem with allowing the CO2 reaction to occur as you mix your Kalk in a container without Vinegar is that you are mixing it in a comparatively small quantity of water that contains only a very limited amount of CO2. So, instead of having enough CO2 to go all the way to useful Bicarbonate ions (HCO3-, or Alkalinity) as you want it to, the chemical reaction stops at the undesirable Carbonate ion (CO3--). This is what sets the stage for the Calcium ions to precipitate out as useless solid Calcium Carbonate while still in the mixing container -- the Kalk mixes with SOME CO2, but not with ENOUGH CO2. If your mixing container contained ample CO2, i.e., enough to fully react all the Kalkwasser as Bicarbonate ions, you would indeed then want to do all the mixing with CO2 right there in the container. It's only because there's not enough CO2 present in the small container that you need to limit the mixing to avoid precipitation. So, you've actually hit on one good reason WHY we want to add the Vinegar to the mixing container -- the Acetic Acid in the Vinegar provides the equivalent of enough CO2 to take the reaction all the way to the desired end products for which we drip Kalk -- that is, to produce free Calcium ions and free Bicarbonate ions in solution in our tanks. By using enough Vinegar, we can mix to our heart's content right in the container, and don't need to worry as much about dripping the solution slowly into the tank. We have already driven the reaction all the way to the desired outcome, and provided ample CO2 to produce a balance of free Calcium ions and free Bicarbonate ions. This, incidentally, is why Kalk is said to be "ionically balanced" - it produces a one-to-one balance between Calcium and Alkalinity. By the way, the "stoichiometric" amount of Vinegar, i.e., that amount that provides the exact equivalent of enough CO2 to react all the Kalk powder to Calcium and Bicarbonate, turns out to be about 25ml of 5% Acetic Acid per liter of saturated (0.02 moles/liter or 1.5 grams/liter) aqueous Calcium Hydroxide solution (Kalkwasser). I've used 30ml of Vinegar to a
beatle January 17, 2012 January 17, 2012 (edited) I'll have to read up on this. I'm about ready to give up on kalk since I can hardly add any to my tank without sending the pH above 8.4. I use about 2 gallons of top off per day, but only a pint of that is kalk. More than that and I start to have pH issues. Any specific advice for those using a kalk stirrer? I have a monster from GSA. Edited January 17, 2012 by beatle
flowerseller January 17, 2012 January 17, 2012 I'll have to read up on this. I'm about ready to give up on kalk since I can hardly add any to my tank without sending the pH above 8.4. I use about 2 gallons of top off per day, but only a pint of that is kalk. More than that and I start to have pH issues. Any specific advice for those using a kalk stirrer? I have a monster from GSA. How reliable is the pH probe? I've never been a huge fan of adding vinegar to the water being used for top off through a kalk reactor and do not do it myself. Been adding kalk for over 20 years.
beatle January 17, 2012 January 17, 2012 It's off my AC3 and is less than a year old, so I guess it's reliable. I calibrated it when I got it. I also noticed irritated corals when I started dumping in all my ATO through the kalk reactor and pH shot to nearly 8.6. I didn't have a high pH issue until I changed out my 40g sump under the tank for a 75g sump and 40g refugium in the basement. I used kalk before and liked it, but the whole setup including the display was in a basement that probably wasn't ventilated very well, despite being an old drafty house from the 60s. I also didn't have a reactor, just added a few tablespoons of kalk powder to my ATO bucket and gave it a stir before I sent it on its way. I never had a high pH issue. It usually hovered around 8.2 during the day.
flowerseller January 17, 2012 January 17, 2012 Probes are best calibrated at least semi annually. Soak it in vinegar for an hour or two, rinse it off well and place it back in the tank and see how it reads. Also look where you normally place it and see that it's not in an area that is likely to get a fresh blast as the reactor adds. Also that's it's not in an area that is likely to be right close to the output of a skimmer or other extra highly oxygenated area like an over flow. Those can give you an artificially high pH reading.
SkiCurtis January 17, 2012 January 17, 2012 personally adding a kalk stirrer and a dosing pump was one of the best upgrades my tank has ever gotten. sounds like you need one. with a stirrer and the top off you should be good.
Origami January 17, 2012 January 17, 2012 Beatle: Definitely calibrate your probe. It's easy to be off. Surf & Turf: Adding vinegar will definitely raise the the amount of calcium and hydroxide that is in solution. Normally, you would do this by adding vinegar to your top off reservoir. However, because then you have a carbon source in your top off water, it could encourage bacteria to grow in your top off reservoir (will likely show up as a bacterial film). This bacteria will begin to break down the vinegar even before it gets to the kalk stirrer and may reduce the benefits you're looking for. I did this for a while a several years ago, and that's the observation that I walked away with. I quit dosing the vinegar in this fashion because of the bacterial film that developed in my top off container.
surf&turf January 17, 2012 Author January 17, 2012 (edited) Beatle: Definitely calibrate your probe. It's easy to be off. Surf & Turf: Adding vinegar will definitely raise the the amount of calcium and hydroxide that is in solution. Normally, you would do this by adding vinegar to your top off reservoir. However, because then you have a carbon source in your top off water, it could encourage bacteria to grow in your top off reservoir (will likely show up as a bacterial film). This bacteria will begin to break down the vinegar even before it gets to the kalk stirrer and may reduce the benefits you're looking for. I did this for a while a several years ago, and that's the observation that I walked away with. I quit dosing the vinegar in this fashion because of the bacterial film that developed in my top off container. I don't have an ATO and only mix up to enough Kalk to be used up in a day or two. I mix up fresh everytime. I started this morning with 1ml per quart of lime water I'll stay there for a week and increase to 2ml next week. I'll keep everyone posted. Edited January 17, 2012 by surf&turf
flowerseller January 17, 2012 January 17, 2012 I don't have an ATO and only mix up to enough Kalk to be used up in a day or two. I mix up fresh everytime. I started this morning with 1ml per quart of lime water I'll stay there for a week and increase to 2ml next week. I'll keep everyone posted. Is your goal to try and raise Ca? Ca additives could be better because too muck kalk can lower Mg.
BowieReefer84 January 17, 2012 January 17, 2012 Are your nitrates and phosphates already zero? Are your intentions to be able to increase the amount of kalk in solution with the vinegar, or drop your phosphates/nitrates? If your nitrates/phosphates are already at or close to zero I don't think you should use the vinegar.
firecrackerbob January 17, 2012 January 17, 2012 (edited) I began dosing vinegar about 1 month ago... about 2 months ago I upgraded to a ASM G3. It pulled dark skim for about a week, then went pale and watery. Once I began adding vinegar the skim went to a dark mocha again, corals colored up, and began growing noticably better. PH has also been trending upwards since then(started at around 7.9 on average and am now up to 8.15 on avg). your results may vary!!! as for me, I have been very pleased so far. from all the reading I have done, I really dont think there is any danger to experimenting with vinegar\Kalk. if you have good flow and a decent skimmer, you really shouldnt notice any bacerial blooms... and if you do?! stop dosing. just go slow and observe your tank and its inhabitants carefully! Edited January 17, 2012 by firecrackerbob
Reefoholic January 17, 2012 January 17, 2012 Is there a difference btw dosing vinegar or vodka? Some people dose sugar disolved in RODI. In my understanding, it is all a carbon source, is it not?
firecrackerbob January 17, 2012 January 17, 2012 it is indeed all carbon. some people dose 1, 2, or all 3 of the carbon sources you mention. I have so far only focused on vinegar, so cannot speak to the other two. I wanted to get more kalk into solution, so vinegar made the most sense to me. from my reading, if you have a calcium reactor, the other sources may make more sense.
BowieReefer84 January 17, 2012 January 17, 2012 (edited) This article http://reefkeeping.c.../nftt/index.php seems to be the starting point in most peoples research on the subject. Vinegar is 8x weaker than vodka, so if you are using 0.1ml vodka you would use 0.8ml vinegar... Edit - here is a good thread on RC. http://www.reefcentral.com/forums/showthread.php?t=2115592 Edited January 17, 2012 by BowieReefer84
surf&turf January 17, 2012 Author January 17, 2012 Is your goal to try and raise Ca? Ca additives could be better because too muck kalk can lower Mg. Just to maintain CA. I'll keep a check on the Mag to.
surf&turf January 17, 2012 Author January 17, 2012 Are your nitrates and phosphates already zero? Are your intentions to be able to increase the amount of kalk in solution with the vinegar, or drop your phosphates/nitrates? If your nitrates/phosphates are already at or close to zero I don't think you should use the vinegar. Just to keep the kalk in solution. Not really trying to dose a carbon source. Just seems to be an added benifit.
surf&turf January 17, 2012 Author January 17, 2012 I began dosing vinegar about 1 month ago... about 2 months ago I upgraded to a ASM G3. It pulled dark skim for about a week, then went pale and watery. Once I began adding vinegar the skim went to a dark mocha again, corals colored up, and began growing noticably better. PH has also been trending upwards since then(started at around 7.9 on average and am now up to 8.15 on avg). your results may vary!!! as for me, I have been very pleased so far. from all the reading I have done, I really dont think there is any danger to experimenting with vinegar\Kalk. if you have good flow and a decent skimmer, you really shouldnt notice any bacerial blooms... and if you do?! stop dosing. just go slow and observe your tank and its inhabitants carefully! How many ML are you dosing @ this time?
firecrackerbob January 17, 2012 January 17, 2012 the solution I made up was to take white vinegar then add enough kalk to bring the PH of the solution up to ~10. I am currently manually adding about 10ml/day to my tank. my tank volume is about 120 total gal. I started with dosing about 5ml a day for about a week just to observe its effects and as above, noted better skimming, then scaled up to my current amounts.
surf&turf January 17, 2012 Author January 17, 2012 the solution I made up was to take white vinegar then add enough kalk to bring the PH of the solution up to ~10. I am currently manually adding about 10ml/day to my tank. my tank volume is about 120 total gal. I started with dosing about 5ml a day for about a week just to observe its effects and as above, noted better skimming, then scaled up to my current amounts. Thanks, I started @ 1ml/quart of lime water. The article said you could start higher, but I want to start off slow. At 1ml per quart there is still some residue left in the bottom of the container so I have a ways to go to get total saturation.
beatle January 20, 2012 January 20, 2012 I'll pick up some packets and recalibrate my probe. I didn't know they needed to be recalibrated/checked outside of the initial install. I have my controller next to my display and the probe is in the overflow as the line will not reach into the basement where my sump and refugium is.
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