Saturated kalkwasser (or limewater) contains about 40 meq/l alkalinity and 800 ppm calcium with a pH over 12.  How much your tank needs is something you will figure out as you go.  Some people use saturated kalkwasser for all their make-up water.  Some use less then that and others mix up an undersaturated solution.  The only limits to kalkwasser usage is your tank water evaporation and pH.

As far as I know there is no toxicity associated with to high calcium.  But there are water chemisty reasons to not do it.  You will not be able to keep your alkalinity levels up with really high calcium levels.  I would suggest targeting calcium levels at 350 to 450 ppm and alk levels at 2.5 to 4.

By "saturated" do you mean keep adding Calcium Hydoxide to
the water used for top off until no more goes into solution ?

Yes.  What I (and many others) do is just dump lots of power in my container, add water and stir.  The excess kalk will settle to the bottom.  When the kalk solution is gone add more water and stir again.  This can go on until the solids are gone.  But if you use tap water (or let CO2 get into your solution) you will get CaCO3 solid precipitation.  This will not dissolve and weakens the strength of the solution.

That would be a very high molar concentration of Calcium Hydoxide
and intuitively sounds like it might be toxic.

Kalkwasser, Ca(OH)2, is not all that soluble.  Just 1.5 to 2 teaspoons will saturate a gallon of water.  If dosed too fast your tank pH can go too high which can be a problem.  Most people dose slowly for this reason.

i wanted to jump in for a little clarification for myself --- jon, are you saying that if you push your calcium levels to high with kalkwasser that your alk may crash?

BTW... last test results were Ca 430 Alk, 10 dkh, and mag 1350... Temp is 78 and sg is 1.024-1.025.

I wouldnt use straight up 1.5 gallons of Kalkwasser soulution as my make up water...if thats what you were asking.

I have to add about 3 gallons of fresh water for make up water daily to my 135 SPS and Clam tank.  I just drip about 3 qts of Kalkwasser solution via a dripper at a very slow rate during the night.  That works really great for me keeping levels in the 450-500 range and PH in the 8.4 range consistantly

HTH's?

If the calcium and alkalinity is raised to high in the tank by anything it can cause precipition causing a lose of alk/ca/mag.   http://www.utahreefs.com/forum/forum_posts.asp?TID=2208&KW=travis - http://www.utahreefs.com/forum/forum_posts.asp?TID=2208& KW=travis  .

Kalk is great stuff...  you just have to respect it.

Coreyk,  I think your questions have been answered but I'll summarize.

High calcium levels can crash your alk.  High alk levels can crash both your alk and calcium.  And the main reason people dose kalk along with a reactor is for pH control.  The reactor tends to depress pH (due to the CO2 in the effluent) and kalk tends to raise pH.  And heed Imaexpat2 and Travis's caution regarding dosing kalk.  Do it slow and keep an eye on your pH.

Kalk is one of the cheapest "balanced" calcium/alkalinity additives, but also one of the most difficult for many people to use.

A large part of dripping kalk or adding any additive is testing.  If you do not already have test kits I would recommend getting Salifert Calcium, Alkalinity and Magnesium.  IMO testing is what determines calcium/alk needs, not age, number of corals, etc.  Most corals use ca/alk so not just sps or clam tanks require supplementing calcium/alkalinity.

With the sps corals, I would slow down a bit.  They need a mature system, IMO not under 6-months old tank.  They also need a very stable environment low in nutrients...  which new tanks are usually not.

Second, I strongly recommend not using Kalkwasser for a while.

For a beginner, B-ionic is a much safer choice.

A large part of dripping kalk or adding any additive is testing.

YES!  If you regularly test while adding calcium and carbonates to your water you'll significantly reduce the potential for problems.

All newbies should do water testing until they get the hang of the "look" of the tank.

No , you need to teach me the method of visually determining water parameters...  it would some me a lot of time and money.

Fully agree, especially if one is not testing.

Anyone can learn to test their water.  It's not very difficult or expensive.  The experienced eye can see when a tank needs attention quicker then an inexperienced one, but it's always after the fact.  It's just too darn easy to maintain calcium and alkalinity through testing and dosing, which is why I will always recommend it.  As for the myriad of other additives... I would exercise more caution and maybe lean more to the eye of experience.

Jon,

Just checking for clarification - if I remember right, you test your Alk weekly (because it's a good and quick indicator of any problems).  You personally don't need to test the calcium all the time, because you know that your alk is steady.  Correct?  If it was high or low, then you would test Calcium.  Right? 

Btw, my Alk is still tilted to the low side, but my calcium is steady.  Your suggestions are great - it has really helped.  Thanks!!  But I have to admit that I sometimes wonder whether I should be looking toward a calcium reactor.  Reptoreef sounded like he had a nifty calcium reactor.  (Sorry - repto - I can't remember enough of the details to be more detailed. But I'll bet Jon would love it.)

Renee

jfinch wrote: I test my alk weekly, calcium monthly and Mg "less frequent"  If I'm fiddling with my levels and changing my dosing regime I'll test every couple days.

I don't think it would be possible for me to test "less frequently".

Adam

Mark,

Yep I think you got it.  Plus, I don't keep those lame corals that end in pora.  You stony guys what is it that makes you like them? 
Nope, just green stars and polyps for me.

Adam

I test ca/ alk weekly usually...  magnesium every two to four weeks.  I both my tanks the ca/ alk levels can drop pretty quick, the 110g has a ca reactor and I drip kalk so I monitor that regularly (usually get the same readings) and the 55g with mostly softies and some LPS corals and one sps coral but it has a more fluctuating ca/alk level than the 110g... I test it weekly and add ca/alk as needed (which it is needed twice a week) and test nitrates monthly.  All the expeariance in the world wouldn't make my tanks take up any less ca/alk.  Now if you never add additives I guess there would be no reason to test... 

edit: forgot phosphates which I test for monthly... and PH often.

Mark Peterson wrote: Maybe someone else would like to jump in here too. And maybe you know what I'm talking about and I can't see the teasing, I don't know But I will assume that you are serious and attempt to describe what I mean by "the look".

It would seem to me the "look" is healthy vs unhealthy??  I'm I right??  I test to keep from getting a unhealthy tank...  preventive maintenance.  I'm sure you're correct in your observations but at the point you can see signs of trouble, the tank is already in trouble.

Mark Peterson wrote: When we listen to someone tell us about their tank's problems, one of the things we want to know is their testing results. This is a way for them to communicate something of the tanks' condition, without actually examining the tank. And often, as is the case here on the MB, this and other info can lead us to a good diagnosis and effective solution, having never "seen" (or smelled ) their aquarium. $0.02 x 2000+ posts, that's over $20 of advice I've contributed to this MB

I actually don't care what there testing results are.  Maybe I should.  Usually I think people are including that info for Mark, and I just skip right over it.  I usually care about how much rock, corals, fish, and light are in the tank. 

Also, Mark's $.02 x 2000 would be $40

Adam

Just checking for clarification - if I remember right, you test your Alk weekly (because it's a good and quick indicator of any problems).  You personally don't need to test the calcium all the time, because you know that your alk is steady.  Correct?  If it was high or low, then you would test Calcium.  Right? 

I check alk more frequently then calcium because it will vary more then calcium.  And if you're using a balanced calcium/alkalinity additive (CO2/CaCO3 reactor, kalkwasser, b-ionic) then you're adding both in the same proportion that they are most likely being consumed (so yes if alk is fine, calcium will be fine too).  For every 1 meq/l of alkalinity consumed through calcification there will only be 20 ppm of calcium depleted.  If my aquarium is sitting at 3 meq/l and 430 ppm Ca and I stop adding supplements, within a week my alkalinity will drop down to 1.5 meq/l but my calcium will only drop to 400 ppm.  An alk of 1.5 is stressful to calcifying corals, but a calcium level of 400 ppm is fine.  That is why I check alkalinity more frequent then calcium.

When did you start testing for Mg+?? Mr Smarty pants!!!

I've always tested "less frequently" .  I check Mg about once very two to three months.  I've never tested low until just recently.  Apparently my coralline is growing faster and consuming Mg faster then I'm adding it in my fish food and water changes.

Plus, I don't keep those lame corals that end in pora.

Hey if it weren't for those corals (and other calcifiers) you wouldn't  have coral reefs as we know them.  I'm just doing my part to acknowledge they're role

If you don't add calcium and carbonates to a tank with calcifying corals you're most likely stressing them unduly.  They need both to grow.  I would dare to bet that neither Mark or Adam has kept a tank dominated with calcifying corals.  If I neglect my tank (which I occasionally do ) my alk will drop down below 2 meq/l.  The first sign is the growth edge on my plating montiporas lose their color.  It doesn't take a real long time of low alk to cause this, maybe a week.  And once the damage is done it takes a few weeks to get them back to full color and growth rates.  Why should I wait until my montis start to lose their color before acting?

Adam and Mark... you know I love you guys, but I've got a feeling that we will aways be at opposite ends of this discussion.