Kalkwasser and exposure to air

[YBeNormal]

While at the WAMAS meeting today I had a short discussion with someone about the impact of air in kalkwasser (aka limewater) dosing systems. It was one of many side conversations I had today and I apologize that I cannot remember who I was talking to at the time. Anyway, and I know this might stir up some debate, I mentioned that the effects of air on kalkwasser is not as dramatic and some reefers believe it to be and I said that I would share an article I had read on the topic.

 

"The degradation of limewater in air" was written by Randy Holmes-Farley and is posted on Reefkeeping.com. The entire article is very informative and is recommended reading for any interested in the topic but I'm posting the summary here for folks that would rather get straight to the point:

Summary

 

Limewater can lose potency by reacting with carbon dioxide in the air, forming insoluble calcium carbonate. Since calcium carbonate is not an effective supplement of calcium and alkalinity in reef aquaria, the limewater can become less useful through this process. The rate at which this happens in large containers, such as plastic trashcans with loose fitting lids, is much less than many aquarists expect. There is, in fact, little degradation under typical use conditions. Consequently, the dosing of limewater from such large still reservoirs can be just as effective as dosing using any other scheme, and may have substantial advantages. These advantages include simplicity of the system and the ability to use organic acids such as vinegar to boost the potency. The use of a reactor to dose limewater has the advantage of requiring less space, but does not have the oft-stated advantage of eliminating degradation by atmospheric carbon dioxide that is reported to plague delivery from reservoirs.

Most of the testing was conducted on still limewater in a covered or uncovered storage container. Having a small pocket of air in a kalkwasser stirrer or reactor might have a small effect but I'd expect it to be negligible since any CO2 in the air pocket would be depleted within a very short time frame.

[flowerseller]

You could of had that conversation with me but I know you didn't.

 

It's not that it can degrade, it's that it will degrade.

Degrade can be either formation of calcium carbonate making it usless in a kalk reactor or simply the lose of potency due to the number of times it's been asked to become soluable.

Strangely, we use calcium carbonate in our calcium reactors, but in a much lower PH enviornment.

 

So what, either way still works fine, both sealed and unsealed.

I prefer a sealed unit over an unsealed unit and it may just come down to the actual delivery method choice or mix method.

 

A reactor with a powerhead to stir it should be sealed or the carbonate that will form will tear up the impeller quickly.

A reactor with a stir bar, while not as sensitive to the carbonate, will likely go through the kalk faster as it will create more carbonate than a sealed unit.

 

You just bought enough KALK to make it negligable.

Just empty out the reactor from time to time. I do that with my sealed unit even though it has little carbonate matter at the bottom. I siphon off the fluffy stuff and refill. The carbonate matter will look like small scards of glass and thats what kills powerhead impellers.

[flowerseller]

where is everyone else on this?

[NAGA]

I'm here

[flowerseller]

I wish we had a smiley with a bad cold cause I just got one

[dandy7200]

This is just about the only thing me and Chip disagree on and really it's splitting hairs at best. The amount of degridation in the potency of limewater is nill when a constant source of replinishment is happening at the bottom of the reactor. Precipitation stays at the bottom(along with heavy metals), clear liquid is drawn from the top. The advantage of a stir bar design is that this replinishment is always happening 24/7.

 

A reactor with a powerhead to stir it should be sealed or the carbonate that will form will tear up the impeller quickly.

A reactor with a stir bar, while not as sensitive to the carbonate, will likely go through the kalk faster as it will create more carbonate than a sealed unit.

 

This we totally agree on. Since kalk is so incredibally cheap compared to time, I would rather go through a bit more powder than spend my free time cleaning a powerhead of calcium build up. If I had to guess I would say that if 1# of kalk that cost $.32 and normally lasted you 4 months with a sealed container reactor it might only last you 3 months with a unsealed container for a $.08 savings. Even if you were paying for ROWAkalk the savings would simply not be there to justify the increased maintence time IMO.

[NAGA]

I have had this discussion on cmas's board with chip and we don't see it the same way either

[YBeNormal]

I thought this post would stir up some informative discussions but it appears everyone agrees that this is a non-issue or at least a neglible one. Come on folks, where are the hard-core "air is bad" opinions?

[dandy7200]

I thought this post would stir up some informative discussions but it appears everyone agrees that this is a non-issue or at least a neglible one. Come on folks, where are the hard-core "air is bad" opinions?

 

So your more interested in stirring the soup than the kalk huh?

[YBeNormal]

A little of both actually!

[flowerseller]

I thought this post would stir up some informative discussions but it appears everyone agrees that this is a non-issue or at least a neglible one. Come on folks, where are the hard-core "air is bad" opinions?

So what's your opinion?

 

 

I might be wrong but I think in a roundabout way the three that have posted here all agree that air is bad.

Bad in the sense that it does create calcium carbonate, but not bad enough when product is so cheap.

 

I think my difference is in what is defined as a sealed or non sealed unit.

A sealed unit will create less calcium carbonate than a non sealed unit.

 

My expaination ready to be shot holes in.

 

Jeff's reactor lid (a deltec) simply sits on top of his reactor making it unsealed. Jeff?

(allowing for the introduction of "new" air)

Will have calcium carbonate at bottom

 

Grey Sea Aquatics incorporates a nifty twist off o-ringed lid making it sealed or semi sealed. Dan?

(It may or may not allow introduction of "new" air)

May or may not have calcium carbonate at bottom

 

The DIY unit I have is secured by gasket and wing nuts making it completely sealed.

(this does not allow introduction of "new" air, none) Chip!

will have a miniscule amount of calcium carbonate at the bottom

 

My belief is that either the DIY or Grey Sea Aquatics units will form the least amount of calcium carbonate.

 

Is this true or am I out in left field with a nasty head cold?

 

Neither the three of us will tell you not to add the stuff anyway you can.

[ArtC]

None of the units are 'sealed' because CO2 also enters the reactor dissolved in the water...

 

I don't think the diffusion through Jeff's non-sealed reactor lid would make a practical difference, since Holmes--Farley had to run a airstone in the kalkwasser to get the pH to drop in a measurable way. And then only when there was no kalk surplus (not a problem we are currently experiencing!)

 

 

 

 

So what's your opinion?

 

 

I might be wrong but I think in a roundabout way the three that have posted here all agree that air is bad.

Bad in the sense that it does create calcium carbonate, but not bad enough when product is so cheap.

 

I think my difference is in what is defined as a sealed or non sealed unit.

A sealed unit will create less calcium carbonate than a non sealed unit.

 

My expaination ready to be shot holes in.

 

Jeff's reactor lid (a deltec) simply sits on top of his reactor making it unsealed. Jeff?

(allowing for the introduction of "new" air)

Will have calcium carbonate at bottom

 

Grey Sea Aquatics incorporates a nifty twist off o-ringed lid making it sealed or semi sealed. Dan?

(It may or may not allow introduction of "new" air)

May or may not have calcium carbonate at bottom

 

The DIY unit I have is secured by gasket and wing nuts making it completely sealed.

(this does not allow introduction of "new" air, none) Chip!

will have a miniscule amount of calcium carbonate at the bottom

 

My belief is that either the DIY or Grey Sea Aquatics units will form the least amount of calcium carbonate.

 

Is this true or am I out in left field with a nasty head cold?

 

Neither the three of us will tell you not to add the stuff anyway you can.

[dandy7200]

Grey Sea Aquatics incorporates a nifty twist off o-ringed lid making it sealed or semi sealed. Dan?

(It may or may not allow introduction of "new" air)

May or may not have calcium carbonate at bottom

 

Twist lock was eliminated for this reactor. I feel a set on top lid is air tight enough for it's intended application. In a couple weeks I will have an extra one that I plan to use as a demo unit. I'll bring it over and you can try it for a month or so and make your own conclusions as to the effectiveness of this style of reactor vs. what you currently use.

[flowerseller]

Twist lock was eliminated for this reactor. I feel a set on top lid is air tight enough for it's intended application. In a couple weeks I will have an extra one that I plan to use as a demo unit. I'll bring it over and you can try it for a month or so and make your own conclusions as to the effectiveness of this style of reactor vs. what you currently use.

Thanks, but no need.

I remain convinced that all three types work and work just fine .

We know that one over the other will form less carbonate but it's irrelavent in this situation and like Dan said, splitting hairs.

Neither is better except in delivery method.

The sit on top lid will not work in my aplication.

As I mentioned above, it may simply come down to the delivery method chosen.

I use a float switch, and see no reason to change, since the same switch I started with 15 years ago is the same one I'm using today.

Mine is a sealed unit which will form less carbonate but it's main goal is how I deliver it.

In 2 - 3 years I have never had the ph (the stirer) out because it didn't work anymore.

I did remove the powerhead we made them with because it was a poor choice from the start. Other than that, the same 2 - 3 year old ph is in use with no maintinance needed.

The stir bar units came about because many ph stired reactors ate up the ph due to the excess carbonate formed like in the ole trash can method.

 

Having used kalk longer than many have been in the hobby, I can atest to the difference in the old fill a trash can, add kalk to it and then the use of a reactor like the DIY unit I use. My tank exploaded which may seem hard to believe.

I do use a CA reactor now but there's a good reason for that.

 

Heck, I'm still bumping along with the same darn down draft protein skimmer I made 15-16 years ago. Is that wrong too?

 

I have never thought about or read anything along the lines of what ArtC said but I guess that may be the excuse we never where able to identify. That's going to be something interesting to think about when my head cold clears up.

[NAGA]

Thanks for the information ArtC.

[YBeNormal]

So what's your opinion?

 

My opinion--based on several hours of reading and no real-world experience (yet)--is that there is some minor degradation but that it is not significant enough for us to worry about. That is also the response I gave at the meeting when the topic came up. Having purchased a 50# bag of kalk for pocket change pretty much makes it a non-issue for me and a dozen or so other WAMAS members but I still like hearing folks thoughts on the topic.

[dandy7200]

My opinion--based on several hours of reading and no real-world experience (yet)--is that there is some minor degradation but that it is not significant enough for us to worry about. That is also the response I gave at the meeting when the topic came up. Having purchased a 50# bag of kalk for pocket change pretty much makes it a non-issue for me and a dozen or so other WAMAS members but I still like hearing folks thoughts on the topic.

 

Nothing wrong with that Bob, ask lots of questions and always question the answers until you come up with something that works for you and then put it to test to get some of that "real world experience", share and exchange ideas about the results you see.

[Folta]

Hey Bob,

 

It was I who talked to you about the kalk reactor at the meeting. It's very interesting to see just how little air matters, it seems.

[YBeNormal]

Thanks Tim and I apologize for the memory lapse!