Kalkwasser Yes or No?

[brick-brothers]

I know this is a late post but as you can see I'm a late head. ok so I'm thinking about using kalkwasser on my 120g mix reef. I never used this product before so I'm a newbie at it. What equipment would I need for this product? Also I have a cal reactor with co2 tank that i havent been using. Do I just used the cal reactor instead? or is it either or? My last water test was mag 1420, cal 430, alk 7.3, phos 0.

 

[Josh]

How are you currently supplementing Ca/Alk? 2 part?

If you are not seeing Ca drop, then you don't need to change what you are doing. Keep it simple.

If you start adding a lot of SPS/LPS and are having trouble keeping the Ca above 400, then set up and use the Ca reactor (with a controller and solenoid).

If you are having trouble keeping Ca elevated after that (or are seeing your pH drop as a result of the CO2 not blowing off after the water leaves the reactor, you can add Kalk via a stirrer on your ATO/RODI. It is the easiest thing to overdose in your tank so it would be the last thing I would consider when dealing with Ca.

The best bet is the Ca reactor because it provides a very consistent and even flow of Ca and Alk ions.

 

[brick-brothers]

my cal has always been around 500, this is the first time i seen it drop. I havent been dosing my tank for 1 1/2 months. So I guest its best to start up my cal reactor.

 

[brick-brothers]

Just wondering how many reefers are using kalkwasser? Just check my cal reactor and the pump that is suppose to send the cal to the tank is not working properly.

 

[naples]

i would like to know aswell.. my alk drops slow thur out the week in my 150 but i do a 20 gallon wc every week and it keeps all my params up to par. the only one i have a problem with is alk. will using kalk help with my alk.

 

[Josh]

Your Ca dropped from 500 to 430, give it another week and test again. Adding kalk at this point is not going to get you anywhere.

 

[Josh]

will using kalk help with my alk.

Nope.

 

[prattreef]

Why do you say nope? Kalk adds both alk and ca in balanced ratio, so kalk additions will raise alk. What it won't do is change the balance between ca and alk.

 

[naples]

So using kalk will be a good thing? If I have just low alk


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[brick-brothers]

So if I raise the cal to where I want it to be. Will I be able to use kalk instead of the cal reactor?


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[prattreef]

So if I raise the cal to where I want it to be. Will I be able to use kalk instead of the cal reactor?


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Yes provided your ca and alk demands don't outstrip your ability to add kalk ie you evaporate enough water daily to allow you to drip in enough kalk to keep your levels where you want them.

 

[pdnyc69]

+1

why do you say nope? Kalk adds both alk and ca in balanced ratio, so kalk additions will raise alk. What it won't do is change the balance between ca and alk.

 

[brick-brothers]

my cal reactor isnt working properly. Not to mention I havent really used to since I got it. Just been collecting dust. Then yesterday when I decided to start it up again, the pump wasnt pumping water. Just seems like an hassle. I'll give this kalk a try.

 

[Josh]

You can use Kalk once your calcium levels are in line with your Alk.

 

[Boomer]

The first thing you need to know brick is what are your daily Calcium and Alk demands. Meaning, you need to test both each day or each two days for say a week and see how much each drop each day or each two days. Then you "tune" a Calcium reactor or Kalk unit or kalk drip to fit those needs. If one of those does not meet your needs you have to sup the tank by other means. Kalk is the preferred method as it adds nothing extra to the tank, which even Calcium reactors will do to a degree. However, in many systems Kalk is not enough to meet daily needs and in some systems a Calcium reactor is not enough. So, they use both or add a buffer or Caclium sup separately.


People will see a bigger drop in Alk for 3 reasons

1. The Alk is a low number, when compared to Calcium. i.e., 450 ppm Ca++ vs 8 DKH.So, itr is more noticeable.

2. There is allot more Ca++ in the water than Alk. If your Alk was 4 meq / l ( 11.2 dKH) and coral and abiotic precip takes 20 ppm Ca++ / 2.8 dkH, then the dKH would be zero but there is still 370 ppm Ca++ in the tank.

3. The Alk demand is ALWAYS more than the Ca++ demand. Meaning, other reactions use up Alk to try and help buffer the water from other reactions to help keep the pH in more check. And different systems have different demands. You can not really compare tanks.

Issues with Kalk and Reactors:

If your pH is good it can raise it to high with Kalk. Kalk does raise Alk but not as much as a Ca++ reactor, as it can't without serious issues. When Kalk is added it is adding what is called 1 alk unit and a Calcium reactor adds 2 Alk units. Advantage of Kalk over a reactor, in some systems, is it sucks out CO2 faster raising the pH and Caclium reactors usually have excessive CO2 which lowers the pH, as you are adding CO2 to the reactor.

If one can run a system on just kalk and it meets the daily needs that is great and the only way to go. However, you will not see this happen in a sps tanks, as all that Ca++ needed will drive that pH way to high if it is just Kalk. Here you go with a Calcium reactor and kalk sup, mostly for the Kalk sup to bring the pH back up to a better level. I will add that some sps tanks can run on just a calcium reactor. Again, different systems have different demands.

What ever system you choose it is always best to make sure that the Ca++, Mg++ and Alk are in-line FIRST. Meaning, if you had a Ca++ of 390 ppm and want it at 450 ppm and use just kalk your tank will be in big doo-do trouble. As, the pH will be through the roof.

So, what are you doing now for Ca++ and Alk ?

 

[brick-brothers]

Right now I started using the esv part 1 and 2 to bring it back up. I dont have and sps tank. Most of my corals are lps and softies. I 4 med caps growing but thats it for as sps.

The first thing you need to know brick is what are your daily Calcium and Alk demands. Meaning, you need to test both each day or each two days for say a week and see how much each drop each day or each two days. Then you "tune" a Calcium reactor or Kalk unit or kalk drip to fit those needs. If one of those does not meet your needs you have to sup the tank by other means. Kalk is the preferred method as it adds nothing extra to the tank, which even Calcium reactors will do to a degree. However, in many systems Kalk is not enough to meet daily needs and in some systems a Calcium reactor is not enough. So, they use both or add a buffer or Caclium sup separately.


People will see a bigger drop in Alk for 3 reasons

1. The Alk is a low number, when compared to Calcium. i.e., 450 ppm Ca++ vs 8 DKH.So, itr is more noticeable.

2. There is allot more Ca++ in the water than Alk. If your Alk was 4 meq / l ( 11.2 dKH) and coral and abiotic precip takes 20 ppm Ca++ / 2.8 dkH, then the dKH would be zero but there is still 370 ppm Ca++ in the tank.

3. The Alk demand is ALWAYS more than the Ca++ demand. Meaning, other reactions use up Alk to try and help buffer the water from other reactions to help keep the pH in more check. And different systems have different demands. You can not really compare tanks.

Issues with Kalk and Reactors:

If your pH is good it can raise it to high with Kalk. Kalk does raise Alk but not as much as a Ca++ reactor, as it can't without serious issues. When Kalk is added it is adding what is called 1 alk unit and a Calcium reactor adds 2 Alk units. Advantage of Kalk over a reactor, in some systems, is it sucks out CO2 faster raising the pH and Caclium reactors usually have excessive CO2 which lowers the pH, as you are adding CO2 to the reactor.

If one can run a system on just kalk and it meets the daily needs that is great and the only way to go. However, you will not see this happen in a sps tanks, as all that Ca++ needed will drive that pH way to high if it is just Kalk. Here you go with a Calcium reactor and kalk sup, mostly for the Kalk sup to bring the pH back up to a better level. I will add that some sps tanks can run on just a calcium reactor. Again, different systems have different demands.

What ever system you choose it is always best to make sure that the Ca++, Mg++ and Alk are in-line FIRST. Meaning, if you had a Ca++ of 390 ppm and want it at 450 ppm and use just kalk your tank will be in big doo-do trouble. As, the pH will be through the roof.

So, what are you doing now for Ca++ and Alk ?

 

[Boomer]

Then I would get those levels where they need to be, i.e., Ca++ 425, Mg++ 1300, Alk 10 dKH and then try the Kalk and see if it can hold those levels for you. You also need to know your evaporation rate. In a Kalk drip, you drip in enough water so it appears the drip rate is equal to the evaporation rate. The amount of Kalk in the drip will have to be tuned by you. So, there is not to much Kalk or to little Kalk. If a full saturated Kalk drip is not enough then you may have to sup the Ca++ and/or Alk with the two-part or a DIY two part.

 

[KathyC]

Boomer - thanks for all the great info!!
Does dripping kalk help a tank with phosphate issues? I recall reading that somewhere.

 

[Boomer]

Yes, only we do not know to what degree. Craig was the only one to ever do any real tests and IIRC they were not published. Craig had an idea many years ago of taking an old skimmer and running Kalk water through it to pull out PO4. The downfall would be you would need to clean it allot from all the precip and maybe run it once a week. But IIRC he never tried the skimmer idea.

The reaction is

3Ca(OH)2+ 2PO4 ---> Ca3(PO4)2 + 2OH-

That Ca3(PO4)2 is Caclium Phosphate which ends up as a precip or being removed in theory by a normal skimmer. The question is how much by the skimmer and how much settles out on the bottom, which under low pH, in say a SB ,*may go back into solution.

The solubility Ksp of Caclium Phosphates are very low, as in 2.07 x 10^-23 and the solubility of CaCO3 (Calcite) is 3.36 ? 10^−9. So it *should be realllllly hard to dissolve. I say *should be as Ksp's can be misleading. One needs to really look at its rate constant, which are almost impossible to find anywhere as they are rarely done. A rate constant tells you how fast something dissolves in time at x pH. A Ksp only really tells you how much you can hold in solution at saturation, which what is wanted 99.9 % of the time. Solid x may be able to hold allot in solution when dissolved but it can very hard to dissolve. And 99 % of the time smaller the 10^-x is the easier it goes into solution and the more you can hold in solution but not always. The mineral Magnesite, MgCO3 is a good example. Its Ksp is about that of Calcite but is realllllly hard to dissolve. But once dissolved you can hold just as much in solution as Calcite. It Ksp is moderate like Calcite but its rate constant is through the roof and why higher than Calcite.

 

[brick-brothers]

Do you think a tank with lps and softies will used up alot of alk and cal that I would have to run my cal reactor?


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