Calcium levels in aquarium

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 am now using a kalk/ro mix for make-up water(fed via gravity controlled by float valve in sump (next to return pump) and have a ca reactor(affluent fed in at 1st chamber of sump, near chaeto and caulerpa) w/ph controller set at 8.3... all seems stable, at this point at morn:8.2 and eve:8.3. Looking for an ultimate constant level of 8.3. I mix the kalk/ro water in 55 gal bucket(DIY Kalk reactor) with a small powerhead at about midnight and 7 am to saturate while ph is at it's lowest levels.

reptoreef: just wondering what the advantage of both kalkwasser and a calcuim reactor is ?

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?

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.

Mark,
Yes, I will be at the meeting tomorrow and will catch up with
you.

Regarding the tank, I did use an aragonite substrate (Carib Sea
Aragonite and some crushed coral) and luckily I only had four
SPS frags. Two of those croaked suddenly after I purchased
my own RO unit and started doing large water changes (more
on that in a couple days) and the other two don't look that great
since. Everything else in the tank are softies and they are
almost all doing very well although the Xenia is not growing
like a weed as described by others   I have two green chromis
and one yellowhead jawfish. Everything was added very
slowly and the tank is pretty empty relative to what most people
have. The tank was cycled for about four weeks with live rock
before adding a few corals about six weeks ago so its really
about two months old. I thought that perhaps calcium was the
limiting factor for the SPSs so I was going to try Calcium
Hydroxide. I realize that eventually I'll have to get deeper into
water chemistry but I'm trying to take it one step at a time.

BB

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.

Travis wrote: IMO testing is what determines calcium/alk needs, not age, number of corals, etc.

Of course that is totally correct, Travis.
My strong recomendation to him not to use anything at this stage of the game, is based on my experience with newbies screwing everything up by adding chemicals, including b-ionic, when they don't even have a track record of coral growth and water parameters to go on. IME when the proper substrate and some LR is used, the tank does best if left to it's own ecology for at least the first four months.

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

Does this make sense/ do you agree?

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's the school of experience that teaches this ability. When I see an aquarium I look for several things initially, like water color and clarity. (Crystal clear water is not what I look for, btw.) I observe the condition of all the algae especially if there is bright coralline algae, not covered over with softer algae.
Are the coral expanded or shrunken in?
Are the individual polyps fully extended or only partway out?
Do the edges of the coral, especially mushrooms, look burned/white and crinkled?
Is the color right for that coral.
Do the fish seem to be acting healthy or do they appear either sedated or else too active, hiding too quickly upon my approach.
Is there ample water circulation, especially at the surface.

Again, experience is the best teacher of these sometimes subtle conditions.

Also, the smell of a tank is an indicator. A person from the coast of New Zealand was at my home a few years ago. He commented that my tank smelled just like the ocean!

I was helping SMatney with her new, but previously owned, tank the other day. I casually leaned over to smell it. She noticed my move and waited... "This has been a FO tank," I commented. Coral reef tanks have a particular smell. And each one can smell slightly different depending on the mix of coral and filtration methods.

Before anyone gets the idea that I'm setting myself above as some kind of guru, I'm not, but when you've seen as many tanks as I have, you've seen coral at their worst and at their best. Recognizing when they are starting to struggle should be the goal of serious hobbyists, IMO.

Here is the best advice I ever received from a book:
As you daily walk past the tank, try to observe it's general condition. Note any changes from the previous day/week/month. Growth is a very good positive sign, whereas the lack of it most always signals a problem.

I saw Jamison's tank a couple months ago. He pointed out his concern with a receding Frogspawn. I observed that the water current went past a large anemone then hit the Frogspawn, which was about six inches away. We changed the water current by shifting piping, which was also intended to improve pH, and then moved the Frogspawn to the other side of the tank. Jamison told me last night at the meeting, that the coral lost a couple heads, most likely due to exposure to the anemone, but the heads that remain are doing well. He then commented that he still has a problem with algae. I mentioned that he may need to consider more snails and hermits. He embarrassingly nodded in acknowledgment, admitting that he hadn't added more as I had suggested back then.

We live and learn