What causes Calcium to go up?

GoBigGuy · Feb 18, 2015

Hi All,

So I came home today to find my green hammer looking like crap.

My tank is a 180 gallon with 4' sump, skimmer rated for 400gal, reactor running rowaphos, and refugium with cheato.

So I tested my water 2 weeks ago before a 30 gallon water change and my readings were:

pH 8.10
Ammonia 0
Nitrite 0
Nitrate 10
Phosphate .11 ppm
Calcium 523 ppm
Alkalinity 6.832 dkH

Meant to do another test the day after but life got a little crazy but I figured if anything prams should have gone down. The only thing I have done different is I started treating my tank with Polylab Medic, (Active Ingredients: Crystallized Peroxide Salts).

Anyhow I did another water test and my reading were:

pH 8.14
Ammonia 0
Nitrite 0
Nitrate 10
Phosphate .25 ppm
Calcium 572 ppm
Alkalinity 8.568 dkH

Any idea on why my calcium would go up? I know I need to change out my rowaphos and I'll do that tonight but can't figure out why my calcium would be going up when I don't dose calcium. The only thing I add to my tank is what I put in my fish food:

Seachem Garlic Guard
Seachem Entice
Seachem Reef Plus
Brightwell Vitamarin-C

Any ideas?

GoBigGuy · Feb 19, 2015

Anyone?

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805reef · Feb 19, 2015

You said the first test was before a water change and the second test was 2 weeks after a water change... maybe the water change raised your calc?

SJacob164 · Feb 19, 2015

Slowly add alkalinity supplement to your topoff water. should see calcium lower. Don't do any water changes for a bit.

GoBigGuy · Feb 19, 2015

SJacob164 said:

Thanks for the feedback, do you recommend any alkalinity supplement?

Justkeepswimming · Feb 19, 2015

GoBigGuy said:

I noticed that your alk is at 8.5 already. Might want to hold off on the alk dose.. Is your tank sps heavy? Do you supplement anything or just water changes? What are your MAG levels at? What was the salinity of the water you used to do the change and what is the salinity of your tank?
By answering these we can get a better understanding of what could possibly be happening and what you can do...

GoBigGuy · Feb 19, 2015

Justkeepswimming said:

Thanks for the feedback.
I have some montiporas but most of my corals are LPS, polyps and shrooms.
I don't supplement anything, just do water changes with reef crystals
Just picked up a Red Sea test kit today to check my mag so stay tuned
Both the tank and change water is at 1.025

Let me know your thoughts

Thanks!

xmas_one · Feb 19, 2015

I'm curious as to what you are using to test ca that gives you a resolution of one ppm and what you are using that gives alk readings down to a thosandth of a dkh!

Your ridiculously high ca may be coming from the "polyp lab medic" which might include calcium peroxide. I would not use this in my DT, it's an ich/parasite cure that you should probably only using in a QT tank.

Maybe try testing two samples for ca, one with straight tank water and one with straight tank water and a tiny bit of the polyp lab medic.

will21xl · Feb 19, 2015

It might have to do with your mag.. I had the same problem. Low mag with high cal. I balanced the two an got everything where they should be..

rayray · Feb 19, 2015

i was also thinking it might be calcium peroxide (CaO2), but I looked it up and its insoluble in water. If its some other calcium species in that poly lab that they aren't telling you on the label, you would have needed to dose a lot in 180 gallons. Also, low Mg2+ tends to cause low Ca2+.

so... IDK

i would get another test kit first, or test at an LFS

h0ndap0w3r · Feb 19, 2015

Using a Hanna for calcium? If so that's prob your issue.

Low mag will cause your overall perimeters to fly all over the place.... both alk and cal, at least in my experience.

You tested before a water change and again after...that's your cal spike... also for water to have 500+cal might be another set of issues however having high ca isn't the end of the world....high alk will kill things

Confuse · Feb 19, 2015

[MENTION=8157]GoBigGuy[/MENTION] Jeff, how are the fish going! We need updates!

zigginit · Feb 19, 2015

I had the same thing happen to me and never figured it out. I just did more water changes and got tank back to normal. it may be the test kit has small fluctuations in the amount of test water or reagent added.

rayray · Feb 19, 2015

http://reefkeeping.com/issues/2006-06/rhf/

also explained on the BRS magnesium supp page

Calcium Carbonate and Magnesium
Finally, we come to magnesium's role in the calcium carbonate system. The situation for magnesium is appreciably more complex than for pH and alkalinity, but we can continue our same analysis to understand it qualitatively. When solid calcium carbonate is put into seawater, it doesn't just undergo the sorts of "on" and "off" dynamics as calcium and carbonate ions discussed above. Other ions can get into the crystal structure in place of either of these ions. In seawater, magnesium ions get into calcium carbonate crystals in place of calcium ions. Strontium ions may also do so, but their numbers are far lower than magnesium's (about 600 times lower) so they are less likely to become incorporated.

Figures 8 and 9 show how magnesium in solution gets onto and actually into a thin layer of calcium carbonate surface put into seawater. Even though magnesium carbonate itself is soluble enough that it will not precipitate from normal seawater, in a mixed calcium and magnesium carbonate structure, its solubility is lower. So solid, pure calcium carbonate (Figure 8) is rapidly converted to a material with a coating of calcium and magnesium carbonate (Figure 9).

Figure 8. A diagram of solid, pure calcium carbonate first put into a solution containing calcium (white), carbonate (red) and magnesium (black).

Figure 9. A diagram of solid calcium carbonate in a solution containing calcium (white), carbonate (red) and magnesium (black). Magnesium ions replace calcium ions in the structure, and change it chemically so that it no longer looks like calcium carbonate on the surface. The magnesium penetrates a short distance into the surface, but cannot penetrate the entire structure.
This coating has some very important effects. The primary effect is that it makes the surface no longer look like calcium carbonate, so calcium and carbonate ions that land on it no longer find the surface as inviting as before. The magnesium ions have altered the surface in a way that does not hold calcium and carbonate as strongly, and so the "off" rate of any newly landing calcium and carbonate ions is higher (Figure 10). Consequently, even if the driving force to deposit calcium carbonate is still there, the magnesium has gotten in the way and doesn't allow it to happen (or keeps it from happening as fast).

Figure 10. Calcium and carbonate ions landing on the magnesium-modified calcium carbonate surface no longer find it as attractive as a pure calcium carbonate surface, and do not remain attached to it.
The extent to which magnesium gets onto calcium carbonate surfaces depends strongly on the amount of magnesium in solution. The more there is, the more it gets onto the surfaces. If magnesium is lower than normal, then it may not adequately get onto growing calcium carbonate surfaces, allowing the deposition of calcium carbonate to proceed faster than it otherwise would, potentially leading to increased abiotic precipitation of calcium carbonate from seawater onto objects such as heaters and pumps. Often the inability to maintain adequate calcium and alkalinity despite extensive supplementation, and the precipitation of significant amounts of calcium carbonate on heaters and pumps, are signs that the water has inadequate magnesium.

GoBigGuy · Feb 20, 2015

So I did another test using the Red Sea test kit and my calcium measured in at 375ppm

Do I believe Hanna or Red Sea?

Fly5150 · Feb 20, 2015

Is it possible your doing the test wrong?

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GoBigGuy · Feb 20, 2015

Well now I just did my API test kit and got a third number!

Hanna - 572
Red Sea - 375
API - 480

I have been following the directions to a T on all of them so not sure what the hell to believe. I guess I will try and redo the tests a second time and see if anything changes

rayray · Feb 20, 2015

Shoulda just did salifert, done.

GoBigGuy · Feb 20, 2015

So just retested with Hanna and Red Sea and Hanna was even higher than yesterday and the Red Sea tested the same

What causes Calcium to go up?

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