Kalk slurries

[Hobster]

I know this has been discussed many times. I still do not quite understand. I have your books, have done many searches, waded through threads which end up basically take one one to other threads and searches.
So we start with 1/16 tsp in a cup of water (which would be 1tsp/gal) Not to exceed a pH jump of more than .1 or .2.
OK so far. But how soon can one add the next addition??
This second, or third addition would then increase the pH more that .1 or .2 points. So do we give the tank a "shot" in the morning, midday, night? 3/16 of a tsp of kalk is not going to add much Ca??
Maybe a cookbook recipe, please.
Thank you.

 

[willjeff]

I also have been playing around with this. The idea that I plan on using is to get a container to hold the slurrie in and attatch a drip line to it. Such as a iv tubing, with a valve attatched to the end. Let this drip via gravity. Just make sure to keep track of your levels by testing. this way you can turn up the rate or turn it down depending on the levels. Hope this helps.

 

[Hobster]

I currently dose Kalk through top off. I am trying to find out more on the "slurry" /dump and pour method one gal of water is saturated with 2 tsp of Kalk, so how does one add more than that without sending ph, alk through the roof?? I am not setting up an IV bag and can not be adding little shots all day. 1/16 tsp in a cup of water would only be 1 tsp in 1 gal of water.

 

[willjeff]

Ok I see what your talking about. Has dosing the kalk through top off water created any problems?

 

[Hobster]

No, no problems at all. It adds a balanced Ca and Alk, keeps pH stable, helps with phosphate. I only evaporate about 1 gal/day so as Anthony stated it does not keep up with the Ca demand when corals are growing. I need to supplement some extra Ca every week (2 part).Lots of folks dose Kalk through top off.

 

[willjeff]

No matter how it is done it sounds like a very good thing to do. When I get home afterwork I will be figuring out some sort of configuration.

 

[Hobster]

Anthony?

 

[Anthony Calfo]

no such recipe, my friend... each aquarium has such very different daily needs for calcium.

You need to first test and determine your individual tanks needs.

Start by testing your calcium.

then... wait three days without adding any calcium supplements and test your calcium again (this gives us a clearer idea of the difference on hard to read test kits).

Dive the difference in those three days by... three, to give you an idea of your daily demand for calcium.

Then, add small shots (starting with 1/8-1/16" tsp) of kalkwasser slurry (cold water mixing) at night or after the lights have gone out.

Do not add kalkwasser by day, my friend, as it raises pH.

Since pH rises when the lights are on and falls after they go out (respiration of zooxanthellate organisms)... adding kalk at night has a stabilizing effect on pH.

And increase the shot amount as needed to simply reach your daily demand for calcium.

Once you figure it out... its a simple 30 second scoop, mix and shoot.

Now that all said... I should add that most folks would be much better served (safety and consistency) with employing a calcium reactor (two stage).

I use both FWIW

 

[Hobster]

And increase the shot amount as needed to simply reach your daily demand for calcium.

Once you figure it out... its a simple 30 second scoop, mix and shoot

I follow all that you wrote but still do not get how to avoid a large pH spike.

Just for example if we start out with 50 gals and a pH of 8.0. to raise Ca by say 20 ppm would require a little of 1 gal limewater (2 tsp) so adding a slurry of say 1/4 of that (1qt) would raise the pH to probably around 8.2 or more. Here lies my problem/question. How soon after this inital increase can we then add more and bump it up to 8.4 ?? How much lag time between doses? Of course if the example starts out with a higher pH of say 8.3 it would not take much to go over 8.5.

Thanks

 

[Hobster]

^

 

[Anthony Calfo]

your tank's pH should not be moving more than .2 in a given 24 hour cycle frankly... else you have problems (gas exchange, excess CO2, etc that exceed the potential correction with your kalk slurries).

in your 75 gallon tank... even if you had 20 fast growing sps colonies... we are still talking a fraction of a tsp of kalk each day to satisfy your daily demand for calcium. If you are adding more and its not moving your Ca or pH up high/fast enough... then you may have an imbalance in the system (usually from misdosing liquid Ca/Alk products) and the Ca in your kalk slurry is just harmlessly settling out as insoluble.

Dude... with a 75 gall... please just do the test above (3 days without, then test Ca again... divide by three, and then see how much of a tsp it takes daily to meet that demand).

My guess is that you haven't tried it yet and are working out the theory... or, you have tried it and are getting the precip (and need to do a large water change to bring the water quality back to even keel).

I don't mean to be short here, bro... but you are making this much harder than it needs to be.

Truly... it's simple.

If you have up to know been dripping in 1 gall of limewater per night with 1/4tsp of Calcium hydroxide in it (because you have tested and know thats how much calcium you need... not because you are dosing Ca to your tank in obeyence of the evap rate!). Then... you can take the same known safe 1/4 tsp of calcim hydroxide and mix it in a mug full of cold water and pour it into a strong stream of water (or dilute more and still pour in of course).

The whole point of the slurry is that:

a) cold water dissolves it better

b) most systems require so little calcim hydroxide to meet their needs that it does not need to be dripped in via tedious drip systems, stirrers, etc

thats all, my friend

 

[FrankMcD]

Anthony,
I wanted to clarify this before I make any changes. For a Kalk slurry, I am mixing the amount of kalk that the tank needs (1/2 tsp) with a minimal amount of cold water and then pour that into a strong water flow in the tank? I do not wait for the settlement of undissolved kalkwasser? Thanks, Frank

 

[Anthony Calfo]

exactly correct Frank

Diligent folks that are using traditional kalkwasser (supersaturated solution of calcium hydroxide) have already figured out what their daily need for calcium is and are mixing that into their evap top off water.

If we get lazy or sloppy, you might be putting extra in and having more than a little bit of precip left over. But that's not what we are talking about here.

Back to tanks with know daily Ca demands... the kalk slurry is just as you state: the same amount of Calcium hydroxide needed daily, that otherwise would have been put into evap water

But we are avoiding the formation of some insoluble calcium carbonate (exposure of solution to air in bottle for some hours of drip), or losing some of what we need daily due to settling out before drip is done (assuming it does not clog overnight), tedium of clogged drip lines, etc.

The slurry is just the shortcut. And since most tanks do not need more calcium hydroxide per day than will raise the pH more than .2 in a short period of time (check 15-30 minutes later)... most folks can simply add a single shot daily and meet the demand.

Now all of that said... if the tank is very mature with massive coralline algae growth, or is a 200 gall aquarium with 50 large and fast growing stony corals... we are indeed looking at an exception here

But most folks do not have such setups

 

[Hobster]

Anthony,

Thank you for the reply. I would like to say that I do appreciate your help and have the utmost respect for your writing and dedication to the hobby/industry. I know you speak directly and to the point as do I. It is sometimes difficult to communicate via e mail or post in a forum. Please do understand my perception and feelings regarding your reply.

I need to clarify a few things. I have and continue to test weekly using Salifert tests, and even have a Pinpoint electronic pH monitor. I am a degreed business professional so I do not know where "Dude" came from? I even questioned another member for addressing you as such. I am probably older than you and not someone from SouthPark. I didn't just fall of the turnip truck. I keep a weekly tank log and my daily Ca demand is between 15 to 20 ppm. I can grasp the concept of dissolving small amount s of lime in a cup of water. No theoretical challenge.

You are close as to the amount of livestock in my tank. I have 12 SPS, 5 LPS 2 large clams and assorted frags growing rapidly.

I have been dosing 1 gal of saturated lime (2 tsp per gal) per night.
If I dose 1/2 tsp of Kalk in my tank as a slurry, this raises the pH by .2 pH points.
!/2 tsp of Kalk will raise my Ca by about 5ppm. Which does not come close to meeting my daily demand.

I was only trying to completly understand how the "slurry method" could deliver enough Ca in such a sort time without spiking the pH .

Thank you again.

 

[sfsuphysics]

Sorry to beat this horse to the point where it doesn't need to go to the glue factory but....

Using this Kalk "slurry" at night does this help with the exporting of phosphates via the skimmer as with drips as well?

Also is there a time frame when the shot should be done? I know you said night time, but do we wait for the actinics to go out as well (ie completely dark) and then is there some set time to wait (as I'd rather not have to get up at 1am just to shoot in some kalk).

Finally, when about would that calcium be detectable in the system for measuring purposes by morning?

Ok I lied, double final, is there any special instructions for bringing calcium up due to low calcium levels of salt mix? I recently set up a zoo only tank (which I'm already deviating but with the exception of a few ceriths & pods/microstars there's no other life in the tank) and there's a nice high spot on some rocks under my metal halide lamp I have hanging which I put a nice little pelterformis that was starting to get a little too dirty from my main tank, and I used instant ocean for salt mix and I'm wondering about that low calcium level.

 

[Anthony Calfo]

No worries. There was no intent in the use of the world "dude" beyond a common colloquial and diffusive/jovial address. Trying to make light of the matter for someone that seems a bit intense/uptight, as it were.

I must admit too that it peeves me when folks get into discussions on message boards (affably, constructively or combatively/otherwise) yet do not use their real names. Seems discourteous to be anonymously asking for something (opinions/info) in a community of fellowship as we have here.

Since you have not used your first name here... and I cannot remember if you've shared your given name before, you might think is was fair then for me to assume that you would be as accepting of a common address like "dude" as you would a nickname or moniker/handle like... say "Hobster".

Point being... I apologize for the offense taken, and ask you to reconsider if there really was any offense intended at all?

I'll stand on occasion and address you by any formal titles (seriously) if you prefer.

Regarding your calcium queries...

Let me ask, to be clear... are you mixing 2 teaspoons of calcium hydroxide in 1 gallon of (DI/RO, etc) water each night to make your limewater solution? If so... how exactly are you getting all two teaspoons to dissolve in 1 gallon of water? I'm nearly certain this is not occurring (beyond sat point). So... either all 2 tsp are making it into the tank with a fast enough drip (see below... this is a/THE problem) as a supersat solution or slurry, or the mention of 2 tsp is moot because it is simply far beyond what can typically be dissolved in 3-4 liters of water and less Ca (than 2 tsp CaOH nightly) is actually entering the tank.

As for the 1/2 tsp of kalk slurry that raises your pH by .2pp, does this maintain for some hours afterwards? To be more specific... after the initial spike in pH (within the first 15 - 30minutes) are you not seeing a drop? If your calcium demand was so high that a 1/2 tsp legitimately did not dent your daily Ca needs... then(!) your needs for carbonates (ALK) would be in step too for skeltogenesis/calcification (dropping ALK levels). Are you having trouble maintaining ALk as well?

Or... perhaps a liquid buffer is skewing this dynamic?

With the livestock you have mentioned... it does sound like a (wonderfully/not overstocked) typical reef aquarium. And I seriously doubt your daily Ca demand is very high.

I'm wondering if your daily drop in Calcium is not from adding too much calcium too fast (if that full 2 tsp is indeed going in with a drip that is fast enough that the CaOH does not settle in the limewater bottle rather than enter the tank). It could be causing a precip of the matter that is being (mis)read as a larger daily demand from Calcium than you really have from calcification of corals, algae, etc.

What exactly is your daily demand in ppm for this system/group of corals, my friend?

Anthony

 

[Anthony Calfo]

cheers, Mike


very good question about the phosphates. Short answer - yes. But longer answer - what phosphates are we talking about? The ones in source water... or tank water? For the former... we don't want the slurry to precip it, as the slurry is being introduced wholly to the tank.

This raises the issue of using pickling lime versus reagent grade CaOH. If I were using source water that may have phosphates... then I could use pickling lime (tro precip phosphates in the settled solids of my mixing vessel) and only dose the matter as a limewater drip (not a slurry which would carry the phosphates in).

But... if I wanted to do a slurry, then I'd be sure to use reagent/high quality CaOH (fee of its own impurities to some high degree) and only use demineralized source water for the same reasons. Thus... little or no impurities are carried in with the lime or the water via a slurry.

As for dosing time... indeed avoid daylight and peak pH times. Caustic CaOH will only make that higher/worse (possibly stressful or dangerous). Always does kalk at the lower pH times of day.

I like to test my calcium 24 hours after the last dose (right before the next dose on daily routines). I of course periodically test shortly after a fresh dose to determine the range and rate of consumption.

As for the so-called "low" calcium in salt mixes, please do understand my friend that the salt manufacturers are selling this salt across the nation/world. Some aquarists use extremely soft source water... others use extremely hard water. The salt mix formulations must be tempered so that users on either end of the range are not handicapped by an extreme mix (say... high Ca, eg).

And so... for all aquarists, its our responsibility to know our source water and to finesse it as needed.

Several manufacturers of reef supplements make products for reconstituting demineralized water. That's a good start. But ultimately... what you choose to reconstitute your source water with depends on what is missing (or removed as with RO/DI water). Do test your source water to see if it is skewed (high ALK, but low Ca for example... uncommon,, but does occur). You will want to know this before you start tweaking source water prior to salting.

 

[sfsuphysics]

Alrighty Anthony let me try to answer these. I'm fairly sure the phosphates are not coming from the water source since I use RO/Di water.. but who knows anymore I'm sure I've introduced phosphates over the years since I've had this tank since I was still learning (and doing stupid stuff) heck I've been putting the whole hunk o' frozen food in as well before I saw your "frozen food juice is rocket fuel for algae" comment, so I've been draining it since then still have some cyano but not as much. At current I have a little bottle of Kent Kalkwasser, whether or not that's "high quality" I dont know.


For the 'low calcium' mix, all I know is that its low when mixed from my water source (~300 ppm or whatever units the test is) so I have that to compare to.

 

[Hobster]

Anothony,

I do not think that you intended any offense. I certainly do not need any formalities, Just dislike being called Dude and some of the verbage of ;"just do the test" My guess you have not tried it" really is that simple, implying an imbalance in the system and the like, gave me a feeling that I was some sort of dolt. I know you did not intend that.

Anyway, no problem .Forget about it. Moving on. And if you were ever a fan of the orginal classic SNL. Roseanne Roseannadanna "Never Mind" "It's always something"

I disolve the Kalk in a 30 gal top off tank of ro/di. Per Randys many articles on the subject, 2 tsp of lime to 1 gal water equals saturation. So I am dosing the 1 gal of clear limewater over the course of the night between 12 pm and 6 am . Being balanced the alk is not a problem.
As mentioned above my daily Ca usage is 15 to 20 ppm.
Before using the Kalk drip, I use the SeaChem Ca advantage and also have used a 2 part. either way the rate of Ca consumption is the same.

When dosing the slurry of 1/2 tsp, the inital spike is .2 pH points. I gather it will come down in a hour or so but do not have any documentation of that. I can certainly test for it. I was just going by what you stated a .2 pH rise in a 24 hr period so I figured that was it for that day.

I still can not grasp that 1/2 tsp of Kalk which equals 5 ppm Ca in 50 gals is enough to maintain my system. The test results just do not bear that out. I do not have massive amounts coraline or deposits on the glass, pumps etc.

Anyway, that's about it. Thanks again and

Cheers:beer:

 

[Anthony Calfo]

the actual Ca demand runs a pretty wide gamut among aquarists... but is generally much smaller than most folks would guess.

Put another way... you may recall hearing (even doing) only monthly partial water changes on general marine aquariums. Many folks keep tanks this way. In fact... few newbies do more than 25% monthly. And for many folks with the monthly partials (or less often)... months slip into years and these tanks chug along well enough.

My point here is... if their daily demand for calcium was even say... 30 ppm, how could they make it to the end of the first month without depleting most or all calcium in the system essentially? Not to mention that the water change at the end of the month is only a small partial (does not reconstitute minerals lost in the tank fully)

Yet hundreds of thousands of people for many years have kept healthy tanks with LR and various hardy calcifying organisms just one such a schedule.

The demand for Ca in most of our tanks is remarkably low.

So how do we explain the higher readings of 20ppm Ca demand per day in tanks like yours, perhaps/(yes?) that do not have wicked fast and large numbering stonies, heavy coralline algae, bushels of Halimeda, etc.?

Harmlessly precipping out without the fanfare of a snowstorm? Often so.

This was my wonder above... if some other supplement like a liquid calcium or buffer used had been interfering with the kalk slurry additions? Or if too much slurry was added too fast.

Sigh... the remote diagnostics can be frustrating sometimes I do wish I could be there to see/examine closely.

as a matter of my curiousity if none others... after you've added the 2 tsp of calcium hydroxide to saturate the water... do you have any significant residual left over?