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FAQs on Supplementing With Kalkwasser, Mixing & Storing 

Related Articles: Calcium, Understanding Calcium & Alkalinity, The Use of Kalkwasser by Russell Schultz, Calcium Reactors

Related FAQs: Kalkwasser 1Kalkwasser 2, Kalkwasser 3, Kalkwasser 4, & FAQs on Kalk: Rationale/Use, Calcium Measuring/Test Kits, Sources of Calcium, Calcium Supplements, Dosing Kalkwasser, Kalk Reactors, Kalk Automation, Alkalinity Interactions, About Kalk Use & Other Supplements, e.g. Magnesium, Troubleshooting/Fixing, CaCl2 (Calcium Chloride)/ Pickling Lime Use, Calcium and Alkalinity


Kalk / vinegar      3/15/18
Good afternoon Bob. Hope the knee is getting better.
<Thank you John; not yet>
I was wondering if you could offer any “rule of thumb” on how much vinegar I need to add per gallon of Kalk to extend its shelf life? Thanks!
<Mmm, the simplest organic acid, acetic; aka vinegar... is unfortunately not a very consistent product; and you don't mention what amount of Kalk you're adding per volume. I'd like to offer this quote:
"I add 60ml of vinegar to a gal of Kalk. I keep my Kalk concentration at 2tsp per gal. Use it as a carbon source and to help keep the Kalk in solution better. 60gal cube with 10gal sump. I add 600ml/day of Kalk which is roughly 9.1ml of vinegar dosed a day"
as reasonable for a start. I would caution you to measure/monitor nutrient (NO3) levels, as you may find that your Nitrate in particular drops precipitously, depriving chemosynthetic and photosynthetic life of necessary fertilizer. Bob Fenner>
Re: Kalk / vinegar

Cool! Thanks Bob!
<Pleasure. B>

Kalk Stirrer And Operation   11/10/10
Hi all
<Hello Jim>
I have recently set up a Deltec Kalk stirrer to supplement my calcium reactor. Current water parameters are thus Ca 370 Mg 1350 (maintained with Seachem supplement) dKH 11.2 tank size is 130 gallon.
I run the stirrer as a top off only at night with the saturated (clear) solution running into the sump. Can you give me an indication of how much Kalk to put into the stirrer every week please? Would like to top up the Ca to 420 odd as I'm getting a coralline explosion and will be placing various LPS stonies in the next six months.
I currently put in around 35 grams and let the stirrer run for a day prior to top off at night, this is then dosed with a peristaltic pump attached to a timer. This 35 grams only seems to maintain the calcium at 370.
<You will need to determine that amount. When you mix a fresh batch of Kalkwasser, take a calcium reading of the mix after 24 hours. If it is under 800ppm, you can add a little more Kalkwasser. When you reach close to 800ppm, the total amount of Kalkwasser mix you've added will be the amount you can use for each mix. You cannot exceed 800ppm as that is the saturation point, and no matter how much more Kalkwasser you add to the stirrer, it will never exceed 800ppm.>
Also how often to I swap out the Kalk in the stirrer for fresh? If I remember rightly it was weekly is that correct?
<Once you have used up the newly mixed limewater, the Kalk residue should be discarded and start anew as excessive carbonate build up can raise dKH which in turn can/will cause calcium precipitation. Your
present dKH is a little on the high side. I would maintain no higher than 9 dKH, preferably 7-8 dKH.
Do read here and related articles/FAQs found in the header.
http://www.wetwebmedia.com/calcalkmar.htm >
<You're welcome. James (Salty Dog)>

Re: 20K HID and Actinic Blue Light'¦now Kalkwasser and Nitrate -- 06/10/09
Hi Eric,
<<Hello Oowais>>
Thanks very much for your prompt answer.
<<Quite welcome>>
Normally I use deionized or distilled water to make Kalkwasser water.
But I recently noticed that the deionized water contains 10 ppm of Nitrate.
<<Odd, the deionization process should remove all traces'¦perhaps it is leaching from the containers>>
I would like to know if I can use seawater, with around 0 ppm, to make the Kalkwasser water?
<<I suppose you could'¦though I don't know what kind of result you will get/if the extra salt ions will cause any adverse reaction. Try it and see what happens'¦>>
I just made a coil denitrator and would like to know the output flow rate per hour of the water.
<<This is a balancing act'¦ Start with a fast drip and measure the output for Nitrate and make adjustments accordingly'¦you want as fast a stream as you can get with a 'zero' Nitrate reading>>
Thanking you,
<<Happy to share'¦ EricR>>

Old Kalkwasser -- 04/14/09
Hey guys,
I looked thru your many Kalkwasser FAQs and cannot come to a firm conclusion on an approach to an almost automatic Kalk setup.
I have a 10 gal container that I fill with new RO water once a week via a shut off valve. I have a premeasured cup of Mrs. Wages pickling lime to create the mix of limewater. I then mix up the solution manually and let it sit for at least 10 hours.
<<Sounds good thus far>>
I then run an Aqua-Lifter on a timer to dose the Kalk slowly into the tank at a predetermined drip rate to keep pH within check.
My main question is the leftover Kalk on the bottom of the 10 gal container. Since I have the draw tubing 2' from the bottom of the container, I will never receive ANY of the sediment sitting on the bottom of the container but it will get mixed in when new lime and water is added.
Do you see an issue with this?
It's really convenient to mix up 10 gals once a week, but the larger dosing container is rather cumbersome to pickup and washout weekly. Any advice?
<<What you are doing is fine (but do still figure to give the container a good cleaning 2-3 times a year)... In fact, you can probably just add water and give the old slurry a good stir without adding new Kalk powder for a time or two after. The water can only dissolve 'so much' of the Kalk powder at a time...test the pH of the solution after mixing and if it falls below 11 you know to start adding new powder>>
Thanks, Gary
<<Happy to share'¦ EricR>>

Kalkwasser Magic Number (pH) -- 04/08/09
Hello friends.
I have done like most and have spent oodles of time scouring this forum for the answers I need to all of my questions to find the answers to many other things I wasn't looking for but was good to know anyway.
But I'm not in the mood at this time to hunt for the one question you can easily answer for me if you would be so kind.
I recently purchased a Hanna pH/temp tester, the red one, and have calibrated it. Seems really accurate at least temperature wise as I can compare it with my other thermometers. It takes a few moments to get to its final reading as it slowly moves to the proper degree/pH. Anyway, I have been dosing with Kalkwasser via my 29 gallon Rubbermaid trash can with a slow drip in to my sump. I make up enough to last a week. When I refilled to a week's worth (maybe 15 gallons RO water), before adding new Kalk, I tested the pH of the water and found it to be 11.30.
<<Not unusual'¦often the remaining solids can be stirred/remixed a time or two to create a new 'batch' of Kalkwasser without the need for adding more powder>>
What should the pH be at when it is added to a fresh mix?
<<About 12.0>>
Seems like 11.3 is pretty good for not even having to add more Kalk.
<<Agreed'¦as mentioned>>
I'm sure if I added more Kalk the pH would go up but to what?
<<To about 12 or a bit more. But why not just do it and see for yourself'¦>>
I do know enough to know the old, "if it ain't broke don't fix it", so I'm not going to do anything stupid here while everything is stable and healthy looking, but I would like to know what the magic number or target should be.
<<As long as the pH is 11 or more, I see no need to add more Kalkwasser powder. Just give the new water a good stir and let the solids settle out again (the water can only render in to solution a finite amount of Kalkwasser powder). But'¦ Some folks are also more comfortable with dumping/cleaning/mixing fresh each time'¦is up to you
Also, can those pH calibration fluids that come in those packets be emptied into a plastic bottle or something to store in to be reused later, or once you open it you have to use it once and chuck it?
<<As long as the calibration solution does not become diluted or contaminated it can be reused. The solutions can also be obtained in bulk (e.g. - 220ml bottles), though the single-use packets likely afford the highest degree of accuracy (less chance of contamination)'¦depending on how they are used>>
Thanks cyber friends,
<<Happy to share'¦ EricR>>

Calcium Oxide (Making Calcium Hydroxide) -- 01/22/09 At work I have access to food grade Calcium Oxide CaO (lime). I believe when calcium oxide is mixed with water it is Calcium Hydroxide (Kalkwasser mix). <<A bit oversimplified but yes, the Calcium Oxide 'reacts' with the water during a process called 'slaking' to form Calcium Hydroxide. The byproduct would then again be mixed with water to make the 'Kalkwasser'>> Can I use this instead of Kalkwasser? <<Won't be 'instead of''¦ If you go to the trouble to slake the Calcium Oxide, then the byproduct will be Calcium Hydroxide (Kalkwasser powder)>> I know a concern for Kalkwasser is that there could be harmful impurities in the raw material. I have the Certificate of Analysis for this Calcium Oxide so I know that this material has very low to no harmful impurities. <<Considering most of the organisms we keep can detect values in the parts-per-million, even parts-per-billion range'¦having 'very low' harmful impurities can be quite significant. But even so, this food-grade product is likely fine, and certainly no more of a risk than the grocery store pickling lime used by many hobbyists>> I just wanted to get advice from an expert before I go and do a little experiment at home. <<I'm no chemist, but the reaction of the Calcium Oxide and water will generate a lot of heat'¦and reportedly about double the volume of the solid material. I also do not know how violent (if at all) this reaction will be. I suggest any experimenting be done outside with very small amounts until you get a feel for the process. Be sure to wear eye and skin protection (as a 'base' substance, the Calcium Oxide/Hydroxide is more damaging to your eyes than an acid!) and do research the 'slaking' process before you start. And though not as readily accessible as he once was, you might also see if you can reach Randy Holmes-Farley (a reef hobbyist AND experienced chemist) over at Reef Central for his take on what you want to do>> Thanks for your help. Love the website. Matt Columbus, Ohio <<Happy to share mate. EricR'¦Columbia, SC>>

RO/DI water 11/30/07 Hello <hello Steve> I found many sections on aerating and buffering newly made RO/DI water for water changes and makeup water. My question is if I'm adding Kalkwasser to a gallon of water to drip into my system does this also need to be aerated and buffered first? If RO water has a low PH wouldn't the high PH Kalkwasser offset this? <Your question is a good one. pH is lower after coming out of a RO unit because many of the "minerals" that would buffer pH have been removed. Once the water flows from the RO to the DI unit it has ALL the minerals removed, leaving pure water. This water has 0 TDS and is a very "soluble solvent". This means it is eager to absorb any mineral content that it exposed to. Therefore, mixing it with Kalkwasser (Calcium Hydroxide) will immediately have a reaction. The pH will soar up to 9.0 and the hardness will soar to 8-12DKH. This is good for a Saltwater tank as it adds calcium and buffer to the tank. As far as making it goes, add your dry powder to your 1 gallon jug, then shake very well so that you dissolve as much as possible. Then let settle so that you go from cloudy water to clear water. The only thing you want to add to the tank is the clear water. Then just drip that in overnight each day or as necessary (depending on your rate of evaporation) Hope this helps-Rich.. aka. Mr. Firemouth) Thanks

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