calcium crash

[discusdean]

is there any one amongst the reef nuts that could solve a mystery my wonderfull!! reef is all okay exept for a low calcium level that i just cannot maintain above 250ppm .
i have a cacium reactor running 24/7 and this is pouring out 400 -450 ppm and i do regular water changes but still to no avail i am not sure if it is just the fact the the corals that i have are pulling it out quicker than i put in or what as i have at least thirty acro and other sps species in the reef.

[Woodstock]

Are you certain your ca test kit is correct? What are your alk & magnesium levels? Have you ever had a calcium precipitation event?

Read: Chemistry and the Aqurium Article

[Brucey]

OK, how big is your tank (what SPS / Clam etc population have you in your tank), what is the calcium reactor rated up to, what is your alk level and as Doni said, it may be worth testing with two types of test kits to get a correct reading.
Brucey

Oh, by the way. I would not advise running a reactor 24x7. The reactor effluent PH has to be below 6.9 for it to be working properly and during lights off hours, this can be a very risky business. HTH

[mopecula]

Like some have said, I would have another calcium test kit and test for calcium it maybe that your test kit is bad. Also magnesium need to be three times as much as your calcium, so if you have 400 for cal then your mag needs to be 1200. This will help keep your alk and cal in ballance. Calcium reactors are not really for calcium they actually maintain alkalinity and in doing so they keep up the calcium as a by product.
Mo

[NaH2O]

I would just be repeating, but I'll do it anyway. Verify your test kit first. What is your salinity level, alk, pH, etc? Calcium Reactors, to me, are a way to maintain your Calcium levels based on the demand of the tank. If your test kit is correct, then try a different means of supplementation, then adjust your reactor accordingly. Also, when performing a water change, be sure your change water (mixed at least 24 hours prior) has the desired calcium/alk parameters. Just make sure you double check your test kit before you start any supplementation.

Here is a link for you: Reef Chemistry Calculator. You can select a choice of supplementation to aid in raising your calcium or alkalinity.

Hope this helps!

[jhnrb]

I have used sea lab 28 on my past 125 reef with good calcium results 500+ while running a calcium reactor, but, read other posts above as your other parameters need to be correct in order for additional calcium to be effective. I also agree with all to get a 2nd test to verify your test kit is accurate. just adding add calcium may not resolve your problem unless the other levels mentioned in above posts are also correct. hope this helps.

[cheeks69]

Calcium reactors are not really for calcium they actually maintain alkalinity and in doing so they keep up the calcium as a by product.

I'm having difficulty understanding this, could you eleborate ???

I would not advise running a reactor 24x7

Brucey many that run the CR 24/7 also drip kalk or use a Nielsen Reactor in conjunction to keep ph at the proper level.

Calcium levels in the sea and in our aquaria are dependant on several factors. These are:

CO2 levels
PH
Alkalinity
availabilty of required elements
Carbon dioxide , when mixed with water forms a weak acid called Carbonic Acid. Obviously this has a low PH. When this acid comes in contact with the required element of Calcium in the form of aragonite or other calcerous gravel, it has the effect of dissolving it and allowing the components to go into sollution. This is the basis for most of the methods of Calcium additions to our tanks.

The following equations describes what happens when we mix calcium Hydroxide with water

(1) Ca(OH)2+H2O<-> Ca2+2OH- + H2O
Calcuim Hydroxide and Water form a saturated solution called Kalkwasser or Lime water. This solution has a very high PH around 12. When adding Kalkwasser one has to be careful about not raising the PH of the tank water too high or too quickly. CO2 used in conjuction with Kalkwasser will help to prevent this from happening.

This equation represents what happens when CO2 is added to the water:

(2) CO2 + H2O <--> H2CO3<--> H+ + HCO3- <--> 2H+ + CO32-
This reaction shows that when CO2 is added to seawater both Hydrogen carbonate and carbonates are added. When you use both methods the tank water is provided with Calcium and Carbonate ions together. Unfortunately only a small amount of Calcium will be added by using Kalkwasser alone because you are limited by its high PH for one ,if you do not inject CO2 and because you can only use kalkwasser to refill the water lost to evaporation.

[discusdean]

Thanks for the advice guys have bought another calcium test kit and this tests out with in 10ppm of the other which means that the calcium level is around 280 -30ppm which is still to low. the following are my test results as of twenty min ago and and would apreciate any other ideas as my last option seems to be kalkwasser but this would be a first so any sure fire ways to dose this would be good.

ph- 8.2
alk- 3.2
calcium- 300
amm- 0
nitrite- 0
nitrate- less than 5
phos- 0.2

the bio load on the tank fish wise is very low as only four fish in system but the coral level is a lot higher.

2x gonipora
1x mother colony monipora
5x frag monipora
3x frag acropora hysterix
1x mother colony birds nest
5x frags acropora sp(unknown)
1x trumpet
1x brain (large)
2x hammerhead(medium)
1x bubble(large)
1x giggas clam
3x maxima clam
2x plate corals(unknown)

as i write this it seems i have more hard corals than i thought along with the thirty odd snails that is quieta load.

[Woodstock]

Magnesium level?

http://www.advancedaquarist.com/issues/mar2002/chem.htm

When Can Calcium Carbonate Precipitate from Seawater?

One situation in which calcium carbonate can precipitate involves adding calcium carbonate seed crystals of some type to seawater. In many cases, this action will initiate precipitation of calcium carbonate (and magnesium as well). This precipitation typically does not proceed until all of the supersaturation is gone, but is stopped by some other processes (see below).

A second situation where precipitation takes place is if the supersaturation is pushed to unusually high levels. This can be caused by a rise in pH, a rise in temperature (discussed below), or more obviously, by a rise in either calcium or carbonate.

After some solid calcium carbonate has entered the system (either the ocean or a tank), either by precipitation or by addition by the aquarist (e.g., calcium carbonate sand), precipitation will begin immediately. Interestingly, several things stop the precipitation in seawater, permitting the ocean to be supersaturated. Without these processes, it is unlikely that the ocean could remain supersaturated, and might even make it impossible for corals to maintain skeletons without expending considerable effort to prevent dissolution.

What processes inhibit continued precipitation of CaCO3 onto a growing crystal? The main thing happening in normal seawater is likely the impact of magnesium. It does two critical things :

1. Magnesium holds onto carbonate ions and reduces their free concentration, thereby reducing the likelihood of precipitation onto calcium carbonate surfaces.

2. Magnesium gets onto the growing surface of the crystal, essentially poisoning it for further precipitation of calcium carbonate.

Note that while both of these processes inhibit precipitation of calcium carbonate, the first actually increases the solubility, whereas the second does not. It is worth noting that the solubility of calcium carbonate in seawater is about 26 times higher than in freshwater at the same temperature, and this first effect of magnesium is one of the reasons. The second process above does not make calcium carbonate any more soluble. In a sense, it inhibits the pathway between soluble calcium and carbonate ions, and the solid calcium carbonate that would form.

[Woodstock]

http://www.advancedaquarist.com/issues/nov2002/chem.htm

Corrections for Zone 3

Zone 3 problems are a little harder to correct, and are fairly common. It is, in fact, the problem in the real question posed at the beginning of this article (it doesn’t say so there, but the alkalinity was 3.2 meq/L). This problem is typically caused by overdosing alkalinity RELATIVE to calcium, but does not necessarily imply that calcium is either too high or too low (though it is almost always too low). To correct problems in this zone, monitoring of calcium and alkalinity values during correction is especially important.

One more word about this zone before getting to solutions: Many tanks end up here because aquarists are trying to correct pH problems by adding “buffer.” In my opinion, one should not try to correct any pH problem by simply adding an alkalinity supplement. If you are low on alkalinity, it is a fine course of action to raise the alkalinity. But if alkalinity is OK, or even high, adding an alkalinity supplement to alter the pH may simply create a worse problem. Better solutions to pH problems are discussed in this recent article6.

If this problem is extreme (i.e., you are far from the line at the right hand edge of zone 3), then water changes may be the best way to correct to the problem. In most cases, however, water changes aren’t necessary.

I would advise correcting this problem by adding a calcium chloride supplement until you have moved into the target zone (or zones 1 or 2 that you can then treat as described above) as shown in Figure 4. Almost any brand of calcium chloride will do (Kent Turbo Calcium, Kent Liquid Calcium, ESV, etc.). Certain other calcium supplements may also be OK (such as just the calcium component of the two-part calcium and alkalinity additive systems), but you do not want to add any alkalinity. You CANNOT use limewater or a calcium carbonate/carbon dioxide reactor to correct this problem. Any of the balanced calcium and alkalinity additive systems will move you parallel to the line at the edge of the zone, while you want to move over to it, and cross it.


Figure 4. A graph showing how to correct values within zone 3 by adding a calcium additive, such as calcium chloride (the blue arrow).

If calcium is less than 400 ppm, I’d suggest using this handy online calculator7 to determine how much dry calcium chloride is necessary to move back to the target zone. Note that it is a minimum estimate because it does not know how much alkalinity you have, so it cannot know if you are only raising calcium directly (which it calculates) or are also precipitating calcium carbonate (when alkalinity is high this will probably happen, but is typically not a problem other than that it uses up some of what you add).

If the calcium is above 400 ppm in this zone (unlikely, but it does happen), then you can safely either do nothing until it drops and you need to add more calcium, and treat it as suggested in the previous paragraph, or you can add some calcium immediately, move into zone 1, and then just let it drop on its own.

[NaH2O]

I would pick up a product to increase your calcium (i.e. Turbo Calcium, etc), and use the link I provided earlier in the thread. This will help you determine the proper dosage to the level of calcium you want, but do it slowly. From there you can tweek your reactor based on your tank's consumption. Also, I would try and lower your phosphates.

[NaH2O]

I completely forgot to mention - your gigas clam is probably taking a huge hit on your calcium, combine that with the other clams and hard corals, which explains to me why its low. How big is the gigas and how long have you had it (were your calcium problems going on before the gigas was introduced)? From what I understand, gigas utilize alot of calcium. What is your salinity level?

[discusdean]

salinity level is 0.025
mag level unknown getting tested as we speak and the gigas has been in about three months and problem was not as bad as before.
temp 25.c

am already dosing kent liquid calcium to try and correct but not much luck.

[cheeks69]

I would look at the Mag levels like Nikki and Doni mentioned although your alk is within range if the Mag levels were low then I think both cal/alk would be off. I would use Turbo calcium , I have used it before to get my cal levels back to normal and it works great just add slowly and test.

[swissgaurd]

i had this same problem for yrs
just couldnt get the calcium up high enough even using a calcium reactor.
mike from this board helped me with a particular product from warner marine,reefpure concentrated calium supplement.
i now swear buy it the best i have ever used.

vic