The Degradation of Limewater

[Michael950]

I am currently deciding the method I will use when adding Kalk.
I recently purchased a clear Rubbermaid (gallon) jar from Walmart. I use distilled water for top-off and what I am going to do is mix the Kalkwasser mix in a gallon jug and allow it to settle. Then siphon the middle Kalk solution out into the clear jar (I have not done it this way yet so I do not know if it will continue to settle) where it will remain until I need to top off the tank.

I was going to do something similar to the DIY Kalk Dripper (http://reefkeeping.com/issues/2004-06/nftt/index.htm) in the current issue of reef keeping so it will slowly drip. My alternative is to use a pump and float switch, but I would like to minimize my costs right now.

I read (most) of your article on The Degradation of Limewater and I now have some questions,

>Above figure 5:
>Consequently, just about any still container of limewater (that
>is, not stirred or aerated) can be kept near full potency simply
>by adding excess lime solids.

So if kept stagnant, then add more Kalk mix? Doesn't that become wasteful (not the most efficient method)?


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The result of this reaction is visually obvious. The calcium carbonate can be seen as a solid crust on the surface of limewater that has been exposed to the air for a day or two. It also settles to the bottom of the container. Since solid calcium carbonate is not an especially useful supplement of calcium or alkalinity, this reaction has the effect of reducing the potency of the limewater. With sufficient exposure to air, such as by aeration or vigorous agitation, this reaction can be driven to near completion, with little calcium or hydroxide remaining in solution.
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>vigorous agitation, this reaction can be driven to near completion
If there is degradation, due to the calcium carbonate at the bottom and top will the agitation raise the potency?

If I added a pump into the jar, what would need to be done in order to complete the reaction (what method to perform vigorous agitation)?


Thank you for your help.

Michael

[Randy Holmes-Farley]

So if kept stagnant, then add more Kalk mix? Doesn't that become wasteful (not the most efficient method)?

No. There's no need to throw it out each time. If you want saturated limewater, you can always keep some solids on the bottom, Just add more water and lime next time. I'd clean it out once in a while, especially if it became discolored.

If there is degradation, due to the calcium carbonate at the bottom and top will the agitation raise the potency?

If I added a pump into the jar, what would need to be done in order to complete the reaction (what method to perform vigorous agitation)?

I think you misunderstand. You do not want that reaction to proceed. It wastes the lime, forming useless calcium carbonate.

[Michael950]

Is that where the kalk reactors fail to deliver, or does it not apply to the reactors because they are in a sealed system (no exposure to atmosphere)?




I may have missed it but what are some alternatives to buying the Kalk mix [I am currently using Kent Marine Kalkwasser] at the LFS?

Am I waisting my money buying the [Kent Marine] Liquid Calcium as well?


Gracias,

Michael

[Randy Holmes-Farley]

The don't really fail to deliver, except that they may not always be saturated (if that is important, it wouldn't be for me) and can't readily be adapted to use vinegar, if one wants to.

There are many alternatives to limewater for supplementing calcium and alkalinity. This article describes the pros and cons:

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

You may not need the liquid calcium if you use limewater.