AmherstReef
New member
Yes start with 1 tsp per gallon until you know how it affects your PH
Those that use Kalk for top off
- Thread starter Capt_Cully
- Start date
Capt_Cully
Active member
It doesn't matter. The water can only hold so much product. The kalkwasser is "saturated" once the rest of the powder precipitates out and settles on the bottom (after you mix). If you put in too little, you won't see the precipitate on the bottom. I'd be willing to bet, weather you use a tsp or a tbsp per gallon, you'll be ok. As long as you ONLY dose the liquid and NOT the sludge at the bottom, you're good.
blanden.adam
Team RC
If you wind up needing more, you can increase the concentration of the kalk to about 1 tablespoon per gallon (3 tsp/gal) by including 45 mL of 5% white vinegar per gallon to your mix. This is stoichiometric acetic acid, and serves as a carbon dioxide equivalent for the purposes of alkalinity (the bacteria metabolize the acetate to carbon dioxide and water, which can react with the hydroxide in kalk to give you bicarbonate, aka alkalinity). This is the absolute limit though, as if you increase the acetic acid you will actually react away the alkalinity in solution, making it an unbalanced additive.
Gary Majchrzak
Team RC
sheesh. Look at you!
FWIW I don't spike my kalk with vinegar. But who cares?
Cully- I thought you were gonna trade that Ca reactor to ME! LOL
Seriously- I can't keep up with demand over here. Must find a solution!
mr.maroonsalty
New member
I remember bornamen saying he was using straight Dow flakes I think it was around a cup a day on top of his lime and ca rx.
I'm in the same boat trying to decide how to top off with lime water. I had planned. Larger 15-20g reservoir, but realized that because I am plumbing my DI product to the stand I could use a much smaller container, but only because I can not afford a preasurized stirrer. Otherwise I believe I would connect a branch of RO/DI straight to the Rx then to a float in my sump and only worry about clogs and filling the container. For my poor man's version I'm thinking to use a plastic rectangular cat litter bucket with a float and old skool several inches of lime. An aqualifter will connect the reservoir to the float in the sump. Later I may have a ATO tell the aqualifter to pump with the float being a fail safe. Im not often away so I think once a day or so I'll give the bucket a quick stir. I'm curious if an air pump on a timer would be all that is needed for once a day mixing????? Here's the lime dosed I use on a smaller tank which worked fine using just the aqualifter and a drip rate controller:
I'm in the same boat trying to decide how to top off with lime water. I had planned. Larger 15-20g reservoir, but realized that because I am plumbing my DI product to the stand I could use a much smaller container, but only because I can not afford a preasurized stirrer. Otherwise I believe I would connect a branch of RO/DI straight to the Rx then to a float in my sump and only worry about clogs and filling the container. For my poor man's version I'm thinking to use a plastic rectangular cat litter bucket with a float and old skool several inches of lime. An aqualifter will connect the reservoir to the float in the sump. Later I may have a ATO tell the aqualifter to pump with the float being a fail safe. Im not often away so I think once a day or so I'll give the bucket a quick stir. I'm curious if an air pump on a timer would be all that is needed for once a day mixing????? Here's the lime dosed I use on a smaller tank which worked fine using just the aqualifter and a drip rate controller:
S2minute
New member
I use a 5 gal bucket with an L nipple tapped into and about a 1/2" from the bottom. Airline hose to that, that leads to a liter meter III. This lasts me 4 days. I use Approx 95 grams of kalk and mix it with 500 ML of Vinegar to make a 5 gal solution. I let it settle for several hours before the doser kicks in then i just rinse the bucket out when done and start over. I only dose at night. I have a fair amount of precip on the bottom but it seems to work well. I can usually tell if all or most of the Vin is used up because after mixing the only thing i can smell from the mix is lime water or just a hint of vin. My Alk and Ca are at good levels and any left over Vin is food for the Bac. Here is a quote from this read and here s a link to that read:
"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 ½ teaspoon of Ca(OH)2 per liter of mix without any problem, but recommend about 15ml to those new to using Vinegar."
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http://www.reefscapes.net/articles/breefcase/kalkwasser.html
"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 ½ teaspoon of Ca(OH)2 per liter of mix without any problem, but recommend about 15ml to those new to using Vinegar."
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http://www.reefscapes.net/articles/breefcase/kalkwasser.html
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S2minute
New member
What the Kalk does via Chem reaction is convert the solid form of carbon(Vinegar) and enabling the full effect of the Kalk you are trying to dose. So, instead of using just the CO2 that is on your makup water which is very limited, only X amount of the kalk you add will react to it because you only have so much CO2 in the makeup water. Using Vinegar and mixing it with the Kalk BEFORE you add it to your makeup water uses up all or most of your Kalk you add because it has all that solid carbon(Vin) to convert in addition to what CO2 is in your makeup water. So in effect. it could be a FORM carbon dosing but, because the intent is to use your kalk to convert the CO2 before it reaches your system. ....Anything left over after the chem reaction will make it's way to your system in the form of solid carbon for your Bac but, the amount is minimal.
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SkiFletch
New member
Since you're worried about pump reliability for dosing limewater, Is cash a problem for you Cully? I too was worried about proper dosing and decided to go with something that was literally designed to run 24/7. LMI chemical metering pumps (diaphragm pumps) are the way to go. You can find models that run SLOW (like 1 GPD slow) and constant, and are rated for the harshest of chemicals. One common use is for dosing muriatic acid, or liquid chlorine for pools. Beautiful maintenance-free things but pricey. You can find them on Ebay, just be careful if you're buying used... Who knows what's been through them.
They allow you to control dosed chemicals via both/either the stroke of the piston pushing on the diaphragm, or the rpm of it. Fitting them can be a bit tricky as they often use high-pressure fittings, but they can be plumbed directly into your plumbing, or just straight into the sump water itself because the pistons are sealed. This way you don't have to worry about buildup clogging your effluent.
They allow you to control dosed chemicals via both/either the stroke of the piston pushing on the diaphragm, or the rpm of it. Fitting them can be a bit tricky as they often use high-pressure fittings, but they can be plumbed directly into your plumbing, or just straight into the sump water itself because the pistons are sealed. This way you don't have to worry about buildup clogging your effluent.
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SkiFletch
New member
Probably a bad idea. Your air will be contaminated with a lot of CO2 and cause a lot of precipitation of calcium carbonate as a result. I suppiose if you had a covered container and drew air from inside the container to drive the air pump in a kind of closed-loop you would be OK, but forcing outside air into the container is a bad idea.
mr.maroonsalty
New member
Good idea there is room above the float. Making the lid air tight could be a pita. I imagine the air pump would only run 5 min or so a day, just enough to put a fresh couple teaspoons or so into suspension twice a day; do you really think atmospher CO2 would have that much effect?
der_wille_zur_macht
Team RC
I think the thread has moved on past the original question but I'll describe my approach for the sake of posterity. First a review of my system. 360g display, 75g sump. Fairly light coral stock load compared to many tanks means relatively low Ca and alkalinity demands.
In the basement I have a 30g brute that holds RO/DI and is fitted with a mechanical float valve tied directly to the RO/DI system. This means I always have ~30g of RO/DI available. For ATO, there are a pair of electronic float switches in the return compartment of the sump, run on 24v DC, that trigger a relay. The relay controls a 24v DC peristaltic pump that runs at 150ml/min. This provides topoff for evaporation.
For calcium and alkalinity, I use kalk. There is another 30g brute for this purpose. A few times a year, I dump an entire jug of kalk powder into this brute. There is a 24v DC 50ml/min peristaltic pump that pumps kalk from this brute into the sump. The pump is controlled by a timer that allows me to basically control the amount of kalk dosed by increasing or decreasing runtime. The timer splits the dose up over several periods across a 24 hour day, preventing a single big spike each day.
When the kalk brute starts to get low on solution, I refill it directly from the RO/DI brute. To do this, I have a Little Giant pump on a manifold that lets me select where it's pumping to/from by turning valves. The flow from this pump is strong enough that it self-mixes the kalk powder that has settled to the bottom into the incoming RO/DI. This has a few advantages IMHO. First, I don't have to do any stirring or mixing myself. Second, since the pump is pumping RO/DI into the kalk brute, it is NOT exposed to kalk, so I don't worry about it getting destroyed. The only equipment exposed to kalk is the peristaltic dosing pump, and after 18 months of running this system I'm still on the same pump hose with no signs of wear (Somehow I've managed to kill a few motors, but I'm still using the original pump head). Finally, the flow doesn't introduce air into the solution (as you might get with shaking a jug) which helps limit CO2 levels and prevent precipitation.
I test alkalinity and calcium in the display tank about once a month, or more frequently if I have made major changes in the system. After testing, I adjust the on time for the kalk dosing pump if the levels are not correct.
Essentially, I am dosing a fixed volume of kalk determined by testing my calcium and alkalinity levels, and on top of that the ATO is topping off with pure RO/DI to meet my evaporation demands. IMHO this gives me the best of both worlds - I get the "automatic" adjustment of the ATO to changing evap levels (my home is around 30% humidity right now with the heat on, and will be up around 60% in the summer - so evap is definitely not stable year-round). Yet since the topoff is separate from the kalk dosing, I don't have to worry about fluctuating calcium and alkalinity levels as topoff changes - that's the main reason why I don't use the ATO to supply kalk, I don't want the calcium and alkalinity levels to fluctuate as evap changes. Another reason why I like this system is that it's simple and cheap, compared to other forms of topoff and parameter control.
If I ever get to the point where calcium and alkalinity demand outpace topoff, I'll be in a bit of trouble with this approach. If that happens, I'll probably start dosing two part in addition to the kalk, keeping the kalk dose constant somewhere around the minimum evap rate, and letting the topoff continue to compensate for evap.
In the basement I have a 30g brute that holds RO/DI and is fitted with a mechanical float valve tied directly to the RO/DI system. This means I always have ~30g of RO/DI available. For ATO, there are a pair of electronic float switches in the return compartment of the sump, run on 24v DC, that trigger a relay. The relay controls a 24v DC peristaltic pump that runs at 150ml/min. This provides topoff for evaporation.
For calcium and alkalinity, I use kalk. There is another 30g brute for this purpose. A few times a year, I dump an entire jug of kalk powder into this brute. There is a 24v DC 50ml/min peristaltic pump that pumps kalk from this brute into the sump. The pump is controlled by a timer that allows me to basically control the amount of kalk dosed by increasing or decreasing runtime. The timer splits the dose up over several periods across a 24 hour day, preventing a single big spike each day.
When the kalk brute starts to get low on solution, I refill it directly from the RO/DI brute. To do this, I have a Little Giant pump on a manifold that lets me select where it's pumping to/from by turning valves. The flow from this pump is strong enough that it self-mixes the kalk powder that has settled to the bottom into the incoming RO/DI. This has a few advantages IMHO. First, I don't have to do any stirring or mixing myself. Second, since the pump is pumping RO/DI into the kalk brute, it is NOT exposed to kalk, so I don't worry about it getting destroyed. The only equipment exposed to kalk is the peristaltic dosing pump, and after 18 months of running this system I'm still on the same pump hose with no signs of wear (Somehow I've managed to kill a few motors, but I'm still using the original pump head). Finally, the flow doesn't introduce air into the solution (as you might get with shaking a jug) which helps limit CO2 levels and prevent precipitation.
I test alkalinity and calcium in the display tank about once a month, or more frequently if I have made major changes in the system. After testing, I adjust the on time for the kalk dosing pump if the levels are not correct.
Essentially, I am dosing a fixed volume of kalk determined by testing my calcium and alkalinity levels, and on top of that the ATO is topping off with pure RO/DI to meet my evaporation demands. IMHO this gives me the best of both worlds - I get the "automatic" adjustment of the ATO to changing evap levels (my home is around 30% humidity right now with the heat on, and will be up around 60% in the summer - so evap is definitely not stable year-round). Yet since the topoff is separate from the kalk dosing, I don't have to worry about fluctuating calcium and alkalinity levels as topoff changes - that's the main reason why I don't use the ATO to supply kalk, I don't want the calcium and alkalinity levels to fluctuate as evap changes. Another reason why I like this system is that it's simple and cheap, compared to other forms of topoff and parameter control.
If I ever get to the point where calcium and alkalinity demand outpace topoff, I'll be in a bit of trouble with this approach. If that happens, I'll probably start dosing two part in addition to the kalk, keeping the kalk dose constant somewhere around the minimum evap rate, and letting the topoff continue to compensate for evap.
der_wille_zur_macht
Team RC
"That much" is subjective I guess, but it would be too much for me. If you want a small and cheap reactor like that, I'd just drop a really low flow powerhead in and run it once a day for a minute. And plan on replacing it every few months. Or, poke around on eBay and buy a magnetic stir plate. Or find a way to attach a long shaft with a prop at the end to a disco ball motor and let it stir 24/7 (stugray made a reactor like that and posted it in the DIY forum several years ago).
SkiFletch
New member
That's rather similar to what I do DWZM, although in smaller doses/containers/etc. My only difference is using the metering diaphragm pump dialed down and running 24/7 instead of the peristaltic periodically.
MMR, a fully sealed resevoir is not entirely necessary, although the more-sealed, the more-better off you'll be. Tough for me to really comment about the few mins a day thing. Might work fine, might not. You don't REALLY need to stir up the kalk resevoir a lot if your evaporation rate is enough to satisfy your calcium and alkalinity needs though...
MMR, a fully sealed resevoir is not entirely necessary, although the more-sealed, the more-better off you'll be. Tough for me to really comment about the few mins a day thing. Might work fine, might not. You don't REALLY need to stir up the kalk resevoir a lot if your evaporation rate is enough to satisfy your calcium and alkalinity needs though...
blanden.adam
Team RC
Yes it is. It will be completely based on the rate at which your kalk is added, but it is a form of carbon dosing.
This is actually incorrect. What the acetic acid does with the kalk in your ATO is provide a source of protons to react with hydroxide ions from the Ca(OH)2, thus via Le Chatlier's principle, "pulling" more of the kalk into solution. This gives you a more concentrated solution of Calcium-Hydroxide-Acetate (and decreases the amount of "alkalinity" in the bucket".
After the calcium-hydroxide-acetate mixture gets dosed into your tank, the bacteria in your tank metabolize the acetate, using it for energy and releasing a 2 molecules of CO2 and an OH- in the process (thus giving the "alkalinity" it took in the reservoir back). These carbon dioxide molecules can then react with the hydroxide molecules from your Kalk, leaving you with bicarbonate and calcium, plus or minus a few protons depending on other factors in your tank (e.g. amount of acid secreted by bacteria, etc) and some water molecules.
The reason you want to avoid CO2 in your kalk is that the pH (and concentration) is so high that when the CO2 enters solution, it is reacted first to bicarbonate (HOCOO-), which is soluble, and then quickly deprotonated to carbonate (OCOO-2), which then precipitates with the calcium (terribly insoluble). In the lower pH (and concentration) environment of the aquarium, this is not an issue (as long as you add it slowly so the LOCAL pH and concentration do not rise to such a degree as to precipitate calcium carbonate).
I should have been more clear. When I said "stoichiometric" I was speaking in CO2 equivalents. The thing to keep in mind is that every acetate becomes metabolized to 2 carbon dioxide molecules (it is a 2-carbon organic acid. Note the reaction: (CH3COO- + 2O2 --> 2CO2 + H2O + OH-). This means that 45 mL vinegar per 3 tsp kalk gives roughly equivalent amounts of carbon dioxide for the kalk to react with completely (about half what would be calculated if you were simply considering acetic acid:calcium hydroxide). If you go over this amount, you are dosing more acid to your tank than hydroxide, which drops the pH and can deplete alkalinity. Now, of course this equilibrium is more complicated, because the acetate acid can be metabolized to CO2 and then off-gassed from the tank or used for photosynthesis which then raises the pH, but it certainly unbalances the additive to some degree simply because of the free protons. Please see this excellent article by Dr. Randy Holmes-Farley for more details. (Also note, 2 bicarbonates = 1 carbonate (what corals have in their skeletons) + CO2 + water, which is why kalkwasser, although it has 2 molecules of hydroxide per calcium, is balanced. Chemistry is sweet.)
http://www.reefkeeping.com/issues/2005-01/rhf/index.php#7
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mr.maroonsalty
New member
I've been thinking about trying a clock motor with a sec hand to run a stirrer. Also, the precipitate, and all I see that would happen is a waste of a wee bit of mrs wages; true?
blanden.adam
Team RC
If you have extra kalkwasser on the bottom (i.e. you added more kalk than will go into solution, like 3 tsp/gal rather than 2) stirring will cause precipitation, which will just waste some pickling lime (if it settles to the bottom as expected.) If you run out of extra kalk on the bottom to make up for the amount precipitated, then your concentration will also start to drop. With enough kalk on the bottom, this shouldn't become an issue, but the thing is, there is really nothing to be gained by mixing it. Covered kalk remains good for a real long time. What are your concerns about just leaving it alone?
der_wille_zur_macht
Team RC
Adam, I think the concern is mixing "new" RO/DI water when the vessel is used inline as a reactor, i.e. it is fed with fresh RO/DI and the desired outcome is saturated kalk solution dosed into the aquarium. If there is no method to mix the solution, the assumption is it will weaken over time as new RO/DI is added.
This is one of the factors that caused me to go with a very large still container, I can mix new RO/DI in periodically and don't have to worry about keeping the solution saturated as it just sits.
This is one of the factors that caused me to go with a very large still container, I can mix new RO/DI in periodically and don't have to worry about keeping the solution saturated as it just sits.
blanden.adam
Team RC
ahhh, if it's an inline reactor that's the issue, I kinda missed the boat with the question 
Thanks for clarification.
Thanks for clarification.